2011 emission certified lpg fuel system 3.0l gm enginelpg is stored in the fuel tank as a liq-uid....

2011 Emission Certified

LPG Fuel System 3.0L GM Engine

Parts & Service Manual Including Labor Time Guide

Revision A/March, 2011

2011 Emission Certified

LPG Fuel System 3.0L GM Engine for

Parts & Service Manual

Table of Contents

General Information ................................................................................................ 5 An overview of this Service Manual Maintenance ............................................................................................................ 9 General maintenance and maintenance interval information Fuel System ........................................................................................................... 17 An overview of the LPG fuel system and its components LPG Fuel System Diagnosis ................................................................................ 27 How to identify a general problem LPG Symptom Diagnostics .................................................................................. 35 How to correct a specific problem Electrical Section .................................................................................................. 51

Diagnostic Scan Tool ...................................................................................... 53 Using the DST for testing and trouble shooting

Wire Schematic ................................................................................................... 81 Engine wiring schematics Engine Wire Harness Repair ............................................................................. 85 Repairing a wire harness on the vehicle Diagnostic Trouble Codes (DTCs) .................................................................... 89 Application, schematic and DTC specific code information

Servicing the Fuel System .................................................................................... 237 Step by step instructions on how repair and/or replace fuel related Components LPG Parts Diagram ................................................................................................ 255 Illustrations and part views Labor Time Guide .................................................................................................. 299 The labor reimbursed by IMPCO for warrantable service and repairs Definitions .............................................................................................................. 317 Definitions of phrases and acronyms used throughout this Service Manual Appendix ................................................................................................................ 323 Supplemental charts and tables

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General Information

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INTRODUCTION This service manual supplement has been devel-oped to provide the service technician with the basic understanding of the IMPCO certified fuel and emission systems for the 3.0L GM engine. This manual should be used in conjunction with the base engine manual and the OEM service manual when diagnosing fuel or electrical prob-lems. HOW TO IDENTIFY THE ENGINE YEAR

The emission label on the engine will identify the specific model year. SERVICING YOUR EMISSIONS CERTIFIED ENGINE

Any maintenance and repair should be performed by trained and experienced service technicians. Proper tools and equipment should be used to prevent injury to the servicing technician and damage to the vehicle or components. Service repairs should always be performed in a safe envi-ronment and the technician should always wear protective clothing to prevent injury.

For parts or labor to be reimbursed under the IMPCO Technologies Inc. emission warranty, only work performed by IMPCO or OEM trained techni-cians using only IMPCO specified parts will qualify for reimbursement. Refer to the IMPCO Labor Time Guide for additional information.

For parts or labor not reimbursed under warranty, a repair shop or person of the owner’s choosing may maintain, replace, or repair emission-control devices and systems. It is highly recommended that any replacement parts used for maintenance or for the repair of emission control systems be new OEM replacement parts. The use of other than genuine IMPCO replacement parts may im-pair the effectiveness of emission control systems, therefore, the owner should assure that such parts are warranted by their manufacturer to be equiva-lent to genuine IMPCO OEM parts in performance and durability.

FUEL QUALITY LPG engines and fuel systems are designed to operate on HD-5 or HD-10 specification LPG fuel.

Fuel other than HD-5 or HD-10 may cause harm to the engine’s emission control system and a warranty claim may be denied on this basis if op-erators can readily find the proper fuel.* Use of any other fuel may result in your engine no longer operating in compliance with CARB or EPA emis-sions requirements. *Not Applicable in the state of California. FUEL LINE CONNECTIONS Loctite® 567 is recommended for all NPT connec-tions.

Do not use Teflon tape to seal any fuel fit-tings. Fragments of the tape may enter into the fuel system, causing damage or mal-function of critical fuel system components.

AIR FILTRATION REQUIREMENTS Dry filtration is required with maximum recom-mended 4” W.C. restriction @ 75 cfm. IMPCO strongly recommends the use of OEM or factory replacement parts. WASHING Caution should be used when pressure washing near or on an engine’s electrical system. Avoid direct pressure spray on the system electrical connectors. The electrical connectors are splash resistant, but if high pressure water or steam is sprayed directly at the connectors, moisture can become trapped behind the connector seal and cause serious system problems, many of them showing up as intermittent.

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FUEL SYSTEM CAUTIONS

Do not use Teflon tape to seal any fuel fittings. Fragments of the tape may en-ter into the fuel system, causing damage or malfunction of critical fuel system components.

Do not smoke, carry lighted tobacco or use a lighted flame of any type when working on or near any fuel related component. Highly flammable air-fuel mixtures may be present and can be ignited causing personal injury.

Do not allow LPG to contact the skin. LPG is stored in the fuel tank as a liq-uid. When LPG contacts the atmosphere, it immediately expands in-to a gas, resulting in a refrigeration effect that can cause severe burns to the skin.

Do not allow LPG to accumulate in areas below ground level such as in a service pit or underground ventilation systems. LPG is heavier than air and can displace oxygen, creating a dan-gerous condition.

Do not make repairs to the fuel system if you are not familiar with or trained to service Propane fuel systems. Contact the dealer who sold you the engine to locate a repair facility with trained technicians to repair your fuel system.

Unlike gasoline or propane vapors that sink downward. Highly flammable air/fuel mixtures may be present and can be ignited causing personal injury. Always work in well ventilated areas.

WARNINGS, CAUTIONS AND NOTES

This manual contains several different Warnings, Cautions, and Notes that must be observed to prevent personal injury and or damage to the en-gine, the fuel system or personal property.

A “WARNING“ is an advisement that by perform-ing a process or procedure listed in this manual improperly may result in serious bodily injury, death and/or serious damage to the engine or property. Typical Warning Label:

A “WARNING” is an advisement that by performing a process or procedure listed in this manual improperly may result in serious bodily injury, death and/or serious damage to the engine or property.

A “CAUTION” label or statement is used when it has been determine that by performing a process or procedure defined in the manual improperly a less severe result may occur. It could however, result in serious bodily injury, and or serious dam-age to the engine or property damage.

Less severe than WARNING but has the potential to cause injury or dam-age. Also used to notify of situations that could lead to eventual failure, in-jury or damage.

This caution label may also appear in area of this manual that applies to service and repair proce-

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dures. In addition it may also be used to indicate a failure to observe which may influence the terms of the warranty.

An “IMPORTANT” statement generally denotes a situation that requires strict adherence to the as-sembly, tightening, or service procedure. Failure to observe this procedure could result in an un-safe condition or improper performance of the engine or a component.

A “NOTE” statement applies to a specific item or procedure that is to be followed during the servic-ing of the engine or its components. PROPER USE OF THIS SERVICE MANUAL, TOOLS AND EQUIPMENT

To reduce the potential for injury to the technician or others and to reduce damage to the engine dur-ing service repairs the technician should observe the following Steps:

The service procedures defined in this ma-nual, when followed, have been found to be a safe and efficient process to repair the fuel system. In some cases special tools may be required to perform the necessary procedures to safely remove and replace a failed compo-nent.

Tools identified in this manual with the prefix “J” or “BT” can be procured through SPX in Warren, Michigan.

IMPCO tools identified in this manual with a prefix “ITK” can be acquired through OEM Parts Distribution.

IMPORTANT It is important to remember that there may be a combination of Metric and Imperial fasteners used in the installation of the IMPCO fuel system. Check to insure proper fit when using a socket or wrench on any fastener to prevent damage to the component being removed or injury from “slipping off” the fastener.

The fuel system utilizes fuel lines and hoses with high pressure connectors. Always use a wrench of the proper size and torque to the correct value. For hoses with swivel fittings, be sure not to turn the fixed fitting which may cause a twisting or kinking of the hose, possibly resulting in fuel line restriction and/or leak.

Always leak check any fuel system con-nection after servicing! Use an electronic leak detector and/or a liquid leak detection solution. Failure to leak check could result in serious bodily in-jury, death, or serious property damage.

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Maintenance

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MAINTENANCE The maintenance of an engine and related com-ponents are critical to its operating performance and lifespan. Industrial engines operate in envi-ronments that often include hot and cold temperatures and extreme dust. The recom-mended maintenance schedule is listed in this section, however, environmental operating condi-tions and additional installed equipment may require more frequent inspection and servicing. The owner and/or service agent should review the operating conditions of the equipment to deter-mine the inspection and maintenance intervals.

When performing maintenance on the engine, turn the ignition OFF and disconnect the bat-tery negative cable to avoid injury or damage to the engine.

ENGINE BELTS

The engine installed in this equipment uses a ser-pentine drive belt configuration that drives the water pump, alternator and additional pumps or devices. It is important to note that the drive belt is an integral part of the cooling and charging sys-tem and should be inspected according to the maintenance schedule in this section. When in-specting the belts check for: Cracks Chunking of the belt Splits Material hanging loose from the belt Glazing, hardening If any of these conditions exist the belt should be replaced with the recommended OEM replace-ment belt.

Alcohol or Methanol based anti-freeze or plain water are not recommended for use in the cooling system at anytime.

SERPENTINE BELT SYSTEM Serpentine belts utilize a spring-loaded tensioner to keep the belt properly adjusted. Serpentine belts should be checked according to the main-tenance schedule in this section. IMPORTANT: The use of “belt dressing” or “anti-slipping agents” on belts is not recommended. COOLING SYSTEM It is important that the cooling system of the en-gine be maintained properly to ensure proper performance and longevity.

Alcohol or Methanol based anti-freeze or plain water are not recommended for use in the cooling system at anytime.

Do not remove the cooling system pres-sure cap (radiator cap) when the engine is hot. Allow the engine to cool and then remove the cap slowly to allow pressure to vent. Hot coolant under pressure may discharge violently.

NOTE that the LPG vaporizer is connected to the cooling system and the fuel system may be ad-versely affected by low coolant levels and restricted or plugged radiator cores. Therefore, the cooling system must be maintained according to the recommend maintenance schedule in this section and also include: The regular removal of dust, dirt and debris

from the radiator core and fan shroud. Inspection of coolant hoses and components

for leaks, especially at the radiator hose con-nections. Tighten hose clamps if necessary.

Check radiator hoses for swelling, separation, hardening, cracks or any type of deterioration.

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If any of these conditions exist the hose should be replaced with a recommended OEM replacement part.

Inspect the radiator cap to ensure proper seal-ing.

COOLANT

Check coolant level in coolant recovery tank and add coolant as required. Add 50/50 mixture of GM Dexcool antifreeze and water or coolant per engine manufacturer’s instructions. Do not add plain water. Replace coolant per the recommend-ed schedule.

IMPORTANT: The manufacturers of the engine and fuel system do not recommend the use of “stop leak” additives to repair leaks in the cooling system. If leaks are present the radiator should be removed and re-paired or replaced. ENGINE ELECTRICAL SYSTEM MAINTNANCE The engine’s electrical system incorporates com-puters to control various related components. The electrical system connections and ground circuits require good connections. Follow the recom-mended maintenance schedule in this section to maintain optimum performance. When inspecting the electrical system check the following:

Check Positive and Negative cables for corro-sion, rubbing, chafing, burning and to ensure tight connections at both ends.

Check battery for cracks or damage to the case and replace if necessary.

Inspect engine wire harness for rubbing, chaf-ing, pinching, burning, and cracks or breaks in the wiring.

Verify that engine harness connectors are cor-rectly locked in by pushing in and then pulling the connector halves outward.

Inspect ignition coil wire for hardening, crack-ing, arcing, chafing, burning, separation, split boot covers.

Check spark plug wires for hardening, crack-ing, chafing, arcing or burning, separation, and split boot covers.

Replace spark plugs at the required intervals per the recommended maintenance schedule.

Verify that all electrical components are se-curely mounted to the engine or chassis.

Verify that any additional electrical services installed by the owner are properly installed in the system.

Verify that the MIL, charging, and oil pressure lights illuminate momentarily during engine start.

ENGINE CRANKCASE OIL

OIL RECOMMENDATION Select an engine oil viscosity that will best match the prevailing daytime temperature:

The oil must meet GM specification 9986231. Mo-tor oils meeting this spec receive the API (American Petroleum Institute) starburst symbol:

ILSAC GF-4 oils are highly recommended. Oils meeting the SL-4 spec are improved over the pre-vious generation GF-3 oils in many ways Reduced Phosphorous levels (20%) for re-

duced catalyst poisoning Improved oxidation resistance (4X oxidation

inhibitor treat level = 100% improvement)

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Improved hi temp deposit control (1.5X deter-gents = 25% improvement)

It is noted that the GF-4 oils are also “backward compatible” and are equal or better than previous grades of oil in all aspects. OEM’s may opt for higher viscosity oils based on their application experience however GF-4 oils may not be available in these viscosity ranges. In this case it is recommended the OEM utilize high quality oil (API rating SM). CAUTION: Do not to operate your engine with an oil level below the normal operating range. Se-vere engine damage could occur. SYNTHETIC OILS Synthetic oils have been available for use in in-dustrial engines for a relatively long period of time and may offer advantages in cold and hot temperatures. However, it is not known if syn-thetic oils provide operational or economic benefits over conventional petroleum-based oils in industrial engines. Use of synthetic oils does not permit the extension of oil change intervals. CHECKING/FILLING ENGINE OIL LEVEL IMPORTANT: Care must be taken when checking engine oil lev-el. Oil level must be maintained between the “ADD” mark and the “FULL” mark on the dipstick. To ensure that you are not getting a false reading, make sure the following steps are taken before checking the oil level. 1. Stop engine. 2. Allow approximately five minutes for the oil to

drain back into the oil pan. 3. Remove the dipstick. Wipe with a clean cloth

or paper towel and reinstall. Push the dipstick all the way into the dipstick tube.

4. Remove the dipstick and note the amount of oil on the dipstick. The oil level must be be-tween the “FULL” and “ADD” marks.

Engine Oil Dip Stick (Typical)

5. If the oil level is below the “ADD” mark reinstall

the dipstick into the dipstick tube and proceed to Step 6.

6. Remove the oil filler cap from the valve cover. 7. Add the required amount of oil to bring the

level up to, but not over, the “FULL” mark on the dipstick. Reinstall the oil filler cap to the valve rocker arm cover and wipe any excess oil clean.

CHANGING THE ENGINE OIL IMPORTANT: When changing the oil, always change the oil filter. 1. Start the engine and run until it reaches nor-

mal operating temperature.

An overfilled crankcase (oil level being too high) can cause an oil leak, a fluctuation or drop in oil pressure. When overfilled, the engine crankshafts splash and agitate the oil, causing it to aerate or foam.

IMPORTANT: Change oil when engine is warm and the old oil flows more freely. 2. Stop engine

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Engine oil will be hot. Use protective gloves to prevent burns. Engine oil con-tains chemicals which may be harmful to your health. Avoid skin contact.

3. Remove drain plug and allow the oil to drain. 4. Remove and discard oil filter and its sealing

ring. 5. Coat sealing ring on the new filter with clean

engine oil, wipe the sealing surface on the filter mounting surface to remove any dust, dirt or debris. Tighten filter securely (follow filter man-ufacturer’s instructions). Do not over tighten.

6. Check sealing ring on drain plug for any dam-age, replace if necessary, wipe plug with clean rag, wipe pan sealing surface with clean rag and re-install plug into the pan. Tighten to the OEM specification.

7. Fill crankcase with oil. 8. Start engine and check for oil leaks. 9. Dispose of oil and filter in a safe and respon-

sible manner.

FUEL SYSTEM INSPECTION AND MAINTENANCE

LPG FUEL SYSTEM The LPG fuel system installed on this industrial engine has been designed to meet the emission standard applicable for the 2011 model year. To ensure compliance to these standards, follow the recommended maintenance schedule contained in this section. INSPECTION AND MAINTENANCE OF THE FUEL STORAGE CYLINDER The fuel storage cylinder should be inspected daily or at the beginning of each operational shift for any leaks, external damage, adequate fuel supply and to ensure the manual service valve is open. Fuel storage cylinders should always be securely mounted, inspect the securing straps or retaining devices for damage ensure that all lock-ing devices are closed and locked. Check to ensure that the fuel storage cylinder is positioned with the locating pin in the tank collar on all hori-zontally mounted cylinders this will ensure the proper function of the cylinder relief valve.

When refueling or exchanging the fuel cylinder, check the quick fill valve for thread damage. Also verify O-ring is in place and inspect for cracks, chunking or separation. If damage to the o-ring is found, replace prior to filling. Check the ser-vice line quick coupler for any thread damage. IMPORTANT: When refueling the fuel cylinder, wipe both the female and male connection with a clean rag prior to filling to prevent dust, dirt and debris from being introduced to the fuel cylinder. INSPECTION OF THE FUEL FILTER The LPG system on this emission certified engine utilizes an in-line replaceable fuel filter element. This element should be replaced, at the intervals specified in the recommended maintenance sche-dule. When inspecting the fuel filter check the following: Check for leaks at the inlet and outlet fittings,

using a soapy solution or an electronic leak detector and repair if necessary.

Check to make sure filter is securely mounted. Check filter housing for external damage or

distortion. If damaged replace fuel filter.

AIR FUEL MIXER/THROTTLE CONTROL DEVICE MAINTENANCE AND INSPECTION IMPORTANT: The Air Fuel Mixer components have been specifically designed and calibrated to meet the fuel system requirements of the emission certified engine. The mixer should not be disassembled or rebuilt. If the mixer fails to operate or develops a leak the mixer should be replaced with the OEM recommended replacement parts. When inspecting the mixer check for the following items: Leaks at the inlet fitting. Fuel inlet hose for cracking, splitting or chaff-

ing, replace if any of these condition exist. Ensure the mixer is securely mounted. Inspect air inlet hose connection and clamp.

Also inspect inlet hose for cracking, splitting or chafing. Replace if any of these conditions ex-ist.

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Inspect Air cleaner element according to the Recommended Maintenance Schedule found in this section.

Check Fuel lines for cracking, splitting or chaf-ing. Replace if any of these conditions exist.

Verify Throttle body return action to ensure throttle shaft is not sticking. Repair if neces-sary.

Check for leaks at the throttle body and intake manifold.

PRESSURE REGULATOR MAINTENANCE AND INSPECTION IMPORTANT: The Pressure Regulator components have been specifically designed and calibrated to meet the fuel system requirements of the emission certified engine. If the Regulator fails to operate or develops a leak, it should be repaired or replaced with the OEM recommended replacement parts. When inspecting the regulator check for the following items: Check for any fuel leaks at the inlet and outlet

fittings. Check for any fuel leaks in the regulator body. Check the inlet and outlet fittings of the coo-

lant supply lines for water leaks. Check the coolant supply lines for hardening,

cracking, chafing or splits. If any of these con-ditions exist replace coolant lines.

Check coolant supply hose clamp connec-tions, ensure they are tight.

Check to ensure the Regulator is securely mounted and the mounting bolts are tight.

Check the Regulator for external damage. Check the Regulator electrical connections to

ensure the connector is seated and locked. EXHAUST SYSTEM AND CATALYTIC CONVERTER INSPECTION AND MAINTENANCE IMPORTANT: The exhaust system on this emission certified en-gine contains Heated Exhaust Gas Oxygen Sensors (HEGOs) which provide feedback to the ECM on the amount of oxygen present in the ex-haust stream after combustion.

The measurement of oxygen in the exhaust stream is measured in voltage and sent to the ECM. The ECM then makes corrections to the fuel air ratio to ensure the proper fuel charge and optimum catalytic performance. Therefore, it is important that the exhaust connections remain secured and air tight.

Contamination of the HEGO sensor can re-sult from the use of an inappropriate RTV sealer or silicone spray products. Do not use silicone sprays or hoses which are assem-bled using silicone lubricants. Always use “oxygen sensor safe” RTV sealant for repair procedures. Silicon contamination will cause a high but false HEGO signal voltage (rich exhaust indication). The ECM will then re-duce the amount of fuel delivery to the engine, causing a severe driveability prob-lem. If silicone contamination is suspected, remove and visually inspect the sensor ele-ment. If contaminated, the portion of the sensor exposed to the exhaust stream will have a white powdery coating. Always be sure to eliminate the cause of contamination before replacing the sensor.

When inspecting the Exhaust system check the following: Exhaust manifold at the cylinder head for

leaks and that all retaining bolts and shields (if used) are in place.

Manifold to exhaust pipe fasteners to ensure they are tight and that there are no exhaust leaks repair if necessary.

HEGO electrical connector to ensure connec-tor is seated and locked, check wires to ensure there is no cracking, splits chafing or “burn through. Repair if necessary.

Exhaust pipe extension connector for leaks tighten if necessary.

Visually inspect converter to ensure muffler is securely mounted and tail pipe is properly aimed.

Check for any leaks at the inlet and outlet of the converter.

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LPG CERTIFIED ENGINE MAINTENANCE REQUIREMENTS For maintenance or other work that is not performed under warranty, maintenance, replacement, or repair of the emission control devices and systems may be performed by any engine repair establishment or individual.

Perform the following maintenance on the engine at the hours indicated and at equivalent hour intervals thereafter.

This maintenance schedule represents the manufacturer’s recom-mended maintenance intervals to maintain proper engine/equipment function. Federal, State, or Local regulations may require additional or more frequent inspection or maintenance intervals than those speci-fied above. Check with the authority having jurisdiction for details.

Interval Hours

Daily 1000 1500 2000 2500 3000 3500 4000 4500 5000

General Maintenance Section

Visual check for fluid leaks X

Check engine oil level X

Check coolant level X

Change engine oil and filter Every 100 hours or 60 days of operation

Check LPG system for leaks Prior to any service or maintenance activity

Inspect accessory drive belts for cracks, breaks, splits or glazing X X X X X

Inspect electrical system wiring for cuts, abrasions or corrosion X X

Inspect all vacuum lines and fittings for cracks, breaks or hardening X X

Engine Coolant Section

Clean debris from radiator core Every 100 hours or 60 days of operation

Change coolant--GM 6277M specification (Dexcool) 50-50 mixture with distilled water

Every 5000 hours or five years

Inspect coolant hoses for cracks, swelling or deterioration X X X X X

Replace coolant hoses and accessory drive belt Every 2,000 hours or two years, whichever occurs first

Engine Ignition System

Inspect Battery case for leaks or damage X X X X X

Inspect battery cables for damage corrosion or contamination X X X X X

Check all electrical connector retainer locks X X X X X

Replace spark plugs X X X

Inspect crank sensor timing wheel for debris or damage Every 100 hours or 60 days of operation

Clean ignition coil X X X X X

Check spark plug wires for cuts abrasions or hardening X

Replace distributor cap and rotor X

Replace spark plug wires X

Fuel System Maintenance

Inspect air cleaner Every 200 hours, or every 100 hours in dusty environment

Replace fuel filters X X X X X

Inspect Shut-off Valve for leaks and closing X X

Leak check fuel lines, regulator, fuel rail and injectors X X

Check air induction and intake manifold for leaks X X

Check manifold for vacuum leaks X X

Drain Regulator oil build up Every 100 hours or 60 days of operation

Engine Exhaust System

Inspect exhaust manifold for leaks X X

Inspect exhaust piping for leaks X X

Check HEGO sensor connectors and wires for burns, cuts or damage X X

Inspect catalyst for mechanical damage X X Note that propane engines are designed to operate on HD–5 or HD–10 specification LPG fuel. Fuel other than HD–5 or HD– 10 may cause harm to the engine’s emission control system and a warranty claim may be denied on this basis if operators can readily find the proper fuel*. Use of any other fuel may result in your engine no longer operating in compliance with CARB or EPA emissions requirements. * Not Applicable in the state of California.

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LPG Fuel System

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LPG FUEL SYSTEM OPERATION

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DESCRIPTION AND OPERATION OF THE FUEL

SYSTEMS

LPG FUEL SYSTEM

The primary components of the LPG fuel system are the fuel storage tank, regulator, throttle control device, fuel injectors, engine control module (ECM), catalytic converter and Heated Exhaust Gas Oxy-gen (HEGO) Sensor. LPG FUEL TANK

LPG is stored in the fuel tank as a liquid. The ap-proximate pressure of the fuel in the tank is 16.5 bar (240 psi) when the tank is full at an ambient temperature of 27° C (81°F). The boiling point, (temperature at which the liquid fuel becomes va-por) is approximately -40° C (-40° F). When the fuel changes from liquid to vapor the fuel expands and creates pressure inside the tank. When the tank service valve is opened the pressure inside the tank forces the liquid fuel out though the pickup tube located near the bottom of the fuel cylinder.

The service valve mounted in the end of the cylind-er controls the flow of fuel from the tank. By turning the handle to its “open” position, fuel flows out of the tank and into the service line. The service valve is also equipped with a safety feature called an excess flow check valve. This feature reduces the flow from the service valve in the event of a rup-ture of the fuel line or any downstream fuel transport components. A safety valve is built into the tank. Normally set at 25.8 bar (375 psi), it will release pressure to prevent tank rupture due to over-pressurization of the cylinder

Typical LPG Cylinder

1. Liquid Outage Fill Check Valve 2. Pressure Relief Valve 3. Liquid Outage valve w/quick disconnect coupl-

ing 4. Filler Valve 5. Fuel Gauge 6. Vapor Withdrawal Tube (when applicable) 7. 80% Limiter Tube 8. Fuel Level Float 9. Liquid Withdrawal Tube SERVICE LINE LPG flows from the fuel tank to the Regulator via the service line connected to the tank utilizing a quick coupler. The other end of the service line is connected to a bulkhead connector, allowing for a safe means of passing through the sheet metal and into the engine compartment. The service line is made of high pressure hose with special material or possibly tubing which is compatible with the LPG fuel and should always be replaced with an OEM supplied part.

The bulkhead assembly should never be removed. Never run a service line through the sheet metal.

FUEL FILTER LPG, fuel like all other motor fuels is subject to contamination from outside sources. Refueling of the equipment tank and removal of the tank from the equipment can inadvertently introduce dirt, rust and other foreign matter into the fuel system. It is therefore necessary to filter the fuel prior to entering the fuel system components downstream

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of the tank. A replaceable, high pressure, inline fuel filter is built into regulator and another is in line between the regulator and fuel rail. Mainten-ance of the filters is critical to proper operation of the fuel system and should be replaced according to the maintenance schedule or more frequently under severe operating conditions. REGULATOR The Regulator is a combination vaporizer and pres-sure regulating device with a built-in LPG shut-off solenoid valve. The fuel shutoff is a normally closed valve on the vaporizer, controlled by the ECM. The valve is opened is opened momentarily when the ignition is first turned on to allow the sys-tem to pressurize and when the engine is running. When open, LPG passes into the regulator and any liquid LPG is vaporized by heat provided by the en-gine coolant. The fuel vapor pressure is then reduced to approximately 88 kPa (12.6 psi) and delivered to the fuel rail and fuel injectors. The out-let fuel pressure is referenced to the manifold pressure for a more stable idle.

Regulator The regulator and some of components are servi-ceable. THROTTLE CONTROL DEVICE—DRIVE BY WIRE Speed control is maintained by the amount of pres-sure applied to the foot pedal located in the engine compartment, however, in this Drive By Wire (DBW) application, the foot pedal has an electronic

connection with the throttle and there is no direct mechanical (cable) connection between the pedal and the throttle shaft. The ECM monitors the foot pedal position sensor when the engine is running. When the operator depresses or releases the foot pedal, the ECM sends an electrical signal to the motor on the electronic throttle to increase or decrease the an-gle of the throttle blade thereby increasing or decreasing the volume of air delivered to the en-gine. Two internal Throttle Position Sensors (TPSs) provide feedback to the ECM indicating the position of the throttle shaft and blade. De-faults programmed into the ECM software ensure correct speed, load and emission control for all throttle ranges.

A throttle related failure will cause a “LIMP HOME” mode of operation, where the engine has no response to the pedal. THREE WAY CATALYTIC CONVERTER The Catalytic Converter is a component of the emissions system which is designed and cali-brated to meet the emission standards in effect for 2011 model year. The exhaust gases pass through the honeycomb catalyst which is coated with a mixture of metals (such as platinum, palladium, and rhodium) to oxidize and reduce CO, HC and NOx emission gases.

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Three Way Catalytic Converter ENGINE CONTROL MODULE To obtain maximum effect from the catalyst and accurate control of the air fuel ratio, the emission certified engine is equipped with an onboard computer or Engine Control Module (ECM). The ECM is a controller which receives input data from sensors mounted to the engine and fuel sys-tem and then outputs various signals to control engine operation.

One specific function of the controller is to main-tain a closed loop fuel control which is accomplished by use of the Heated Exhaust Gas Oxygen Sensors (HEGOs) mounted in the ex-haust system. The HEGO sensors send a voltage signal to the ECM which then changes the amount of fuel being delivered from the injec-tors to the engine.

Engine Control Module (ECM) The ECM also performs diagnostic functions on the fuel system and notifies the operator of en-gine malfunctions by turning on a Malfunction Indicator Light (MIL) mounted in the dash. Mal-functions in the system are identified by a Diagnostic Trouble Code (DTC) number. In addi-tion to notifying the operator of the malfunction in the system, the controller also stores the informa-tion about the malfunction in its memory. A technician can than utilize a computerized diag-nostic scan tool to retrieve the stored diagnostic code and by using the diagnostic charts in this manual to determine the cause of the malfunc-tion. In the event a technician does not have the computerized diagnostic tool. HEATED EXHAUST GAS OXYGEN SENSOR The Heated Exhaust Gas Oxygen (HEGO) Sen-sor is mounted in the exhaust system to measure the amount of oxygen present in the exhaust stream. The ECM continuously monitors the HEGO measurement to determine whether the fuel air ratio is too rich, too lean and richen or lean the mixture of fuel delivered to the engine. If the ECM determines that a rich or lean condition is present for an extended period of time which cannot be corrected, the ECM will set a diagnos-tic code and turn on the MIL light in the dash.

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The Heat Exhaust Gas Oxygen (HEGO) Sensor

HEGO voltage output.

The Heated Exhaust Gas Oxygen Sensor (HEGO) is an emissions control compo-nent. In the event of a failure, the HEGO should only be replaced with the recom-mended OEM replacement part. The HEGO is sensitive to silicone based prod-ucts and can become contaminated. Avoid using silicone sealers or air or fuel hoses treated with a silicone based lubri-cant.

TMAP SENSOR The Air Temperature/Manifold Absolute Pressure or TMAP sensor is a combination of two sensors: 1) A variable resistor used to monitor the differ-

ence in pressure between the intake manifold and outside or atmospheric pressure. The ECM monitors the resistance of the sensor to determine engine load (the vacuum drops when the engine is under load or at wide open throttle) and may alter the fuel mixture to improve performance and emissions.

2) The Manifold Air Temperature (MAT or IAT)

sensor is a variable resistance thermistor lo-cated in the air intake passage which measures the temperature of the incoming air. The ECM uses the resistance value to monitor incoming air temperature and calculate the en-gine’s airflow requirement. The ECM provides a voltage divider circuit so that when the air is cool, the signal reads a higher voltage, and lower when warm. On cold starts, the ECM ri-chens the fuel/air mixture.

23

TMAP Sensor COOLANT TEMPERATURE SENSOR The Engine Coolant Temperature sensor or ECT is a variable resistance thermistor that changes resis-tance as the engine's coolant temperature changes. The sensor's resistance is monitored by the ECM to determine a cold start condition and to regulate various fuel and emission control functions via a closed loop emission system.

Coolant Temperature Sensor

OIL PRESSURE SENDER The Engine Oil Pressure Sender is designed to en-sure adequate lubrication throughout the engine. It is monitored by the ECM. If the pressure drops, a MIL will occur.

Oil Pressure Sender

IGNITION SYSTEM

The ignition system spark system uses a Crank Position and Camshaft Position sensor for engine timing. A coil assembly contain an ignition coil and an ignition module supplies the ignition spark for the system. The coil is fired for each cylinder over two engine revolutions. The distributor routes each spark event to the appropriate cy-linder spark plug. The plug is fired near the top of the compression stroke to ignite the fuel and air mixture. CAM SENSOR In the 2011 engine the CAM sensor and a cam signal wheel are incorporated into the ignition dis-tributor mounted on the side of the engine block. CRANK SENSOR

Crank Sensor The crank position sensor is a Hall effect sensor that is triggered by a reluctor wheel on the crank-shaft. Two missing teeth are used to determine

24

engines rotational position. The crank sensor is the source of all other ECU functions if this sensor is not functioning the ECU will not see an engine speed and will not provide fuel or spark to the en-gine.

Fuel Rail Assembly and LPG Injectors. The gaseous LPG flows into the fuel rail where it is distributed to the four LPG injectors. At the oppo-site end of the fuel rail to the inlet port there is a Fuel Absolute Pressure (FAP) sensor (also known as a Fuel Rail Pressure Sensor) this sensor allows the ECU to lengthen or shorten the fuel injector pulse width to compensate for variations in the ab-solute fuel pressure supplied to the injectors. This injector assembly has one end inserted into the manifold ports and the other end inserted into the fuel rail ports. There is an o-ring seal on the mani-fold side and an o-ring and split spacer seal on the fuel rail side. The fuel rail holds the injectors in place.

A Spectrum IV Gaseous Fuel Injector

The 2011 saturated drive injectors operate on a two

stage, pilot actuated principal. When the coil is ac-tuated it pulls the primary seal off the primary orifice against the force of the flat return spring. This al-lows gas to flow out of the upper chamber of the injector. Because the orifice supplying the upper chamber is smaller than the primary orifice which is now allowing fuel to flow out of the upper chamber, the pressure drops in this chamber and the now higher pressure in the lower chamber pushes the main secondary seal off the secondary orifice and allows full flow of the injector (this occurs in about 1 to 2 ms). When the coil is de-energized the primary seal is returned to cover the primary orifice by the force of the flat spring and pressure builds in the upper chamber forcing the secondary seal down to seal the secondary orifice and shutting off all flow of gas.

25

LPG Closed Loop Schematic

27

LPG System Diagnosis

28

LPG FUEL SYSTEM DIAGNOSIS

Regulator Assembly

FUEL SYSTEM DESCRIPTION The Engine Control Module (ECM) receives information from various engine sensors in order to control the operation of the engine. LPG is stored in the tank as a liquid and deli-vered under pressure up to 21.5 BAR (312 psi). At Key ON the Regulator allows LPG to flow from the tank through the fuel filter and inside, where fuel is vaporized and reduced in pressure. DIAGNOSTIC AIDS This procedure is intended to diagnose a ve-hicle operating on LPG. If the vehicle will not continue to run refer to Hard Start for prelimi-nary checks. Before starting this procedure, complete the following tasks to verify that liq-uid fuel is being delivered to the EPR: Inspect fuel tank to verify it has a sufficient

amount of fuel.

Verify the manual shut off valve on the LPG tank is fully opened.

Verify that the excess flow valve has not been activated.

Inspect fuel tank to ensure it is properly mounted and rotated to the correct posi-tion.

Inspect the hoses leading from the tank ensuring they are properly connected and do not have any kinks or damage.

TOOLS REQUIRED: 7/16” Open end wrench (for test port

plugs) Test port adapter DST Diagnostic Scan Tool (DST) PRESSURE GAUGES 0-15 PSI Gauge

29

FUEL SYSTEM DESCRIPTION The Engine Control Module (ECM) receives information from various engine sensors in order to control the operation of the Pressure Regulator and Shut-Off Valve. The Shut-Off Valve solenoid prevents fuel flow unless the engine is cranking or running. LPG is stored in the tank as a liquid and delivered under pressure of up to 21.5 BAR (312 psi). At Key ON the Regulator allows LPG to flow from the tank through the fuel filter and inside, where fuel is vaporized and reduced in pressure. DIAGNOSTIC AIDS This procedure is intended to diagnose a vehicle operating on LPG. If the vehicle will not continue to run on LPG, refer to Hard Start for preliminary checks. Before starting this procedure, complete the following tasks to verify that liquid fuel is being delivered to the Regulator: Inspect fuel tank to verify it has a sufficient amount of fuel. Verify manual Shut Off valve on the LPG tank is fully opened. Verify that the excess flow valve has not been activated. Inspect fuel tank to ensure it is properly mounted and rotated to the correct position. Inspect the hoses leading from the tank ensuring they are properly connected and do

not have any kinks or damage.

30

LPG FUEL SYSTEM DIAGNOSTICS

Step Action Value(s) Yes No

1 Were you referred to this procedure by a DTC diagnostic Chart?

Go to Step

(3) Go to

Step (2)

2

Connect the Diagnostic Scan Tool (DST) to the ECM Data Link Connector (DLC) and check for any DTCs. Are any DTCs present in the ECM?

Go to appli-cable DTC

Table

Go to Step (3)

3

Perform the following visual and physical preliminary checks: Check all ECM system fuses and circuit breakers (refer to

Engine Wiring Schematic). Check the ECM grounds for being clean, tight and in their

proper locations (refer to Engine Wiring Schematic). Check the vacuum hoses for damage, splits, kinks and prop-

er connections. Check the fuel system for any type of leak or restriction from

the supply tank. Check for air leaks at all mounting areas of the intake mani-

fold sealing surfaces. Check for air leaks at all intake ducting between intake mani-

fold and air cleaner. Check air cleaner and all vehicle intake ducting for restric-

tions. Check exhaust system for flow obstructions or leaks. Check the ignition wires for the following conditions: Cracking or hardening Proper routing Bare or shorted wires Carbon tracking Check the wiring harness for the following conditions: Proper connections Pinches Cuts or abrasions Were any faulty conditions found in the preliminary checks?

Correct the faulty condition and Go to Step 20

Go to Step (4)

4 Does the vehicle start and run? Go to Step

(9) Go to

Step (5)

5

Check the fuel system for the following conditions: Verify the LPG fuel tank is at least ¼ full. Verify the manual fuel shut-off valve is open and operating

correctly. Verify the high-flow valve has not tripped. Verify the quick disconnect is fully engaged and there are no

kinks or obstructions in the high pressure LPG supply hose. Verify the LPG fuel filter is clean and unobstructed.

Were any faulty conditions found in the fuel supply system?

Correct the faulty condition and Go to Step 20

Go to Step (6)

31


6

Connect a calibrated 0-5” PSI pressure gauge to the pri-mary pressure test port of the Regulator.

Make sure the manual shut-off valve is open and turn the ignition to ON.

Crank the engine and observe the pressure gauge.

Does the pressure gauge indicate the proper primary fuel pressure?

2.0–4.0 PSI

Go to Step (7)

If NO pressure was indi-cated, Go

to Step (14)

If LOW

or HIGH pressure was in-dicated, Go to Step (15)

7

LPG is a gaseous fuel and requires higher secondary igni-tion voltages than gasoline fueled engines. Check the ignition system for proper ignition secondary voltage output with J 26792 or equivalent. Remove the spark plugs and check for the following: Correct plug type for LPG application. Wet electrodes (oil fouling) Cracks Wear Improper gap Burned electrodes Heavy deposits Were any faulty conditions found in the ignition system check?

Correct the faulty condition

and Go to Step

(20)

Go to Step (8)

8

Perform a leak-down test on the engine. Are all cylinder leak-down test results within specification?

<10% leakage

Go to Step (12)

Repair the en-gine as neces-

sary and Go to Step (20)

9

Turn OFF the manual fuel shut-off valve. Start the engine and let it run until it dies. Remove the LPG Temperature Sensor from the Regula-

tor (DO NOT disconnect the electrical connector). Inspect the inside of the low-pressure fuel supply hose

for heavy-end deposits.

Are there any deposits built-up in the low-pressure fuel supply hose?

Go to Step

(16)

Go to Step (10)

32

Step Action Values Yes No

10

Remove the FAP sensor from the Fuel Rail and insert the Pressure Test Adapter and connect to 103 kPa (15 PSI) pressure gauge.

Connect the DST to the vehicle DLC connector and open the DST software.

11

Turn the manual shut-off valve ON. Start the engine and allow it to reach operating temperature.

Compare the gauge secondary pressure reading to the actual pressure on the DST.

Is the gauge secondary pressure within the specified percen-tage of the actual pressure indicated on the DST?

+/-15 kPa (2.2 PSI)

Go to Step 19

Go to Step (11)

12 Turn OFF the manual shut-off valve and let the engine run

until it dies. Turn the ignition OFF.

Go to Step

(14) Go to

Step (13)

13 If turned OFF, turn ON the manual shut-off valve. Disconnect the Lock-off valve electrical connector.

14

Apply 12V to the lock-off valve terminals and observe the pressure gauge.

Does the pressure gauge indicate pressure?

Above 1.0 PSI

Go to Step 17

Go to Step 18

15

Repair or replace the Shut Off Valve (refer to Repair Instruc-tions). Is the action complete?

Go to Step

20 NA

33


16

Inspect the following for heavy-end deposits: Pressure Regulator. Inspect, clean and/or repair as neces-

sary (refer to Regulator Repair Instructions).

Are all actions complete?

Go to Step

20 NA

17 Replace the ECM. Is the action complete?

Go to Step

20 NA

18 Replace the Shut Off Valve. Is the action complete?

Go to Step

20 NA

19

System working correctly at this time. Vehicle may have intermittent electrical connection conditions.

Return vehicle to original condition (but leave the diagnostic equipment connected).

Start the engine and wiggle test the harness while observing the DST Faults Screen and the pressure gauge readings.

Repair any conditions encountered.

Is the action complete?

Go to Step

20 NA

20

Clear any active or historic DTCs (DST Service or Faults Screen).

Clear Adaptive from memory (DST Service Screen). Return the vehicle to original condition. Operate the vehicle under all load and driving conditions for

at least 10 minutes. Park the vehicle with the engine running and connect the

DST to the vehicle’s DLC connector. Open the DST software and switch to the Faults Screen. Let the vehicle idle with no load for at least 30 seconds and

observe the Adaptive 1 fuel correction.

Did the Adaptive 1 fuel correction remain within the specified values?

-15% to +15%

Go to Step 21

Go to Step 24

21

With engine still idling, apply a load with the hydraulic system for at least 10 seconds and observe the Adaptive 1 value. Did the Adaptive 1 fuel correction remain within the specified values?

-15% to +15%

Go to Step 22

Go to Step 24

22

Raise the engine rpms to 75-90% of maximum full governed speed with no load for at least 10 seconds and observe the Adaptive 1 fuel correction. Did the Adaptive 1 fuel correction remain within specified val-ues?

-15% to +15%

Go to Step 23

Go to Step 24

23

With the engine still running at 75-90% of full governed speed, apply a moderate load with the hydraulic system.

Observe the Adaptive 1 fuel correction.

Did the Adaptive 1 fuel correction remain within specified val-ues?

-15% to +15%

Go to Step 29

Go to Step 24

34


24 Was the Adaptive 1 fuel correction less than -15%? Go to Step

(26) Go to

Step (25)

25 Was the Adaptive 1 fuel correction more than +15%? Go to Step

(27) NA

26

Engine is running RICH (system is trying to compensate by de-creasing the amount of fuel). Check the following for any condition which may cause the engine to run RICH: Ignition system (See Step 7). Air cleaner and intake system (including vehicle intake

ducting) for airflow obstructions. Exhaust system for flow obstructions. HEGO for correct switching characteristics.


Go to Step

(28) NA

27

Engine is running LEAN (system is trying to compensate by increasing the amount of fuel). Check the following for any condition which may cause the engine to run LEAN: Intake manifold for leaks. All throttle body gaskets or o-rings for leaks. All vacuum hoses and fittings for leaks. Exhaust system for leaks NOTE: Exhaust system leaks allow for excess O2 to dilute the HEGO sensor giving a false reading. Engine may exhibit signs of a rich running condition but the Adaptive 1 corrections will indicate an excessive positive fuel adjustment. HEGO for correct switching characteristics.


Go to Step

(28) NA

28 Repeat Step 20. NA NA

29

Remove all test equipment except the DST. Connect any disconnected components, fuses, etc. Using the DST clear DTC information from the ECM. Turn the ignition OFF and wait 30 seconds. Start the engine and operate the vehicle to full operating

temperature Observe the MIL Observe engine performance and driveability

Does the engine operate normally with no stored codes? Remove all diagnostic equipment and return vehicle to original condition. Return vehicle to customer.

NA NA

35

Fuel Symptom Diagnostics

36

FUEL SYMPTOM DIAGNOSTICS

Checks Action

Before Using This Section

Before using this section, you should have performed On Board Diagnostic (OBD) Check and determined that: 1. The ECM and MIL are operating correctly. 2. There are no Diagnostic Trouble Codes (DTCs) stored, or a DTC exists

but without a MIL. Several of the following symptom procedures call for a careful visual and physical check. These checks are very important as they can lead to prompt diagnosis and correction of a problem.

Fuel System Check

1. Verify the customer complaint. 2. Locate the correct symptom table. 3. Check the items indicated under that symptom. 4. Operate the engine under the conditions the symptom occurs. Verify

HEGO switching between lean and rich (cycling of voltage). IMPORTANT! Normal HEGO switching indicates the fuel system is in closed loop and operating correctly at that time.

5. Take a data snapshot using the DST under the condition that the symp-tom occurs to review at a later time.

Visual and Physical Checks

Check all ECM system fuses and circuit breakers. Check the ECM ground for being clean, tight and in its proper location. Check the vacuum hoses for splits, kinks and proper connections. Check thoroughly for any type of leak or restriction. Check for air leaks at all the mounting areas of the intake manifold sealing

surfaces. Check for proper installation and leakage around the Regulator and Throt-

tle body. Check the ignition wires for the following conditions: Cracking Hardening Proper routing Carbon tracking Check the wiring for the following items: proper connections, pinches or

cuts. The following symptom tables contain groups of possible causes for each

symptom. The order of these procedures is not important. If the DST read-ings do not indicate a problem, then proceed in a logical order, easiest to check or most likely to cause the problem.

37

INTERMITTENT

Checks Action DEFINITION: The problem may or may not turn ON the (MIL) or store a Diagnostic Trouble Code (DTC).

Preliminary Checks Do not use the DTC table if a fault is an intermittent, the use of the DTC tables with this condition may result in the replacement of good parts.

Faulty Electrical Con-nections or Wiring

Faulty electrical connections or wiring can cause most intermittent problems. Check the suspected circuit for the following conditions: Faulty fuse or circuit breaker, connectors poorly mated, terminals not fully

seated in the connector (backed out). Terminals not properly formed or damaged.

Wire terminals poorly connected. Terminal tension is insufficient. Carefully remove all the connector terminals in the problem circuit in or-

der to ensure the proper contact tension. If necessary, replace all the connector terminals in the problem circuit in

order to ensure the proper contact tension (except those noted as “Not Serviceable”). See section Wiring Schematics.

Checking for poor terminal to wire connections requires removing the terminal from the connector body.

Operational Test If a visual and physical check does not locate the cause of the problem, op-erate the engine with the DST connected. When the problem occurs, an abnormal voltage or scan reading indicates a problem circuit.

Intermittent MIL Illumination

The following components can cause intermittent MIL and no DTC(s): A defective relay. Switch that can cause electrical system interference. Normally, the prob-

lem will occur when the faulty component is operating. The improper installation of add on electrical devices, such as lights, 2-

way radios, electric motors, etc. The ignition secondary voltage shorted to a ground. The MIL circuit or the Diagnostic Test Terminal intermittently shorted to

ground. The MIL wire grounds.

Loss of DTC Memory

To check for the loss of the DTC Memory: 1. Disconnect the TMAP sensor. 2. Run engine under no load until the MIL illuminates. 3. The ECM should store a TMAP DTC which should remain in the memory

when the ignition is turned OFF. If the TMAP DTC does not store and remain, the ECM is faulty.

38

NO START

Checks Action DEFINITION: The engine cranks OK but does not start.

Preliminary Checks None

ECM Checks

Use the DST to : Check for proper communication with both the ECM Check all system fuses engine fuse holder. Refer to Engine Controls

Schematics. Check battery power, ignition power and ground circuits to the ECM. Re-

fer to Engine Control Schematics. Verify voltage and/or continuity for each.

Sensor Checks

Check the TMAP sensor. Check the cam/crank sensors for output (rpm). This can be verified by an

RPM signal on the DST. Check the cam angle sensor for output (rpm).

Fuel System Checks

Verify proper operation of the Shut-off solenoid Valves. Important: A closed Gas supply valve will create a no start condition.

Check for air intake system leakage around the Regulator and throttle

body. Check the fuel system pressures. Refer to the Fuel System Diagnosis.

Ignition System Checks

NOTE: Natural Gas and Propane require higher secondary ignition system voltages for the equivalent gasoline operating conditions. 1. Check for the proper ignition voltage output with J 26792 or the equiva-

lent. 2. Verify that the spark plugs are correct.

Check the spark plugs for the following conditions: Wet plugs (Oil Fouling) Cracks. Wear. Improper gap. Burned electrodes. Heavy deposits. Check for bare or shorted ignition wires. Check for loose ignition coil connections at the coil.

39

Checks Action

Engine Mechanical Checks

Important: The LPG Fuel system is more sensitive to intake manifold lea-kage than the gasoline fuel system. Check for the following:

Manifold vacuum leaks. Venturi vacuum leaks. Engine Vacuum leaks. Improper valve timing. Low compression. Improper valve clearance. Worn rocker arms. Broken or weak valve springs. Worn camshaft lobes.

Exhaust System Checks

Check the exhaust system for a possible restriction: Inspect the exhaust system for damaged or collapsed pipes. Inspect the muffler for signs of heat distress or for possible internal fail-

ure.

40

HARD START

Checks Action

DEFINITION: The engine cranks OK, but does not start for a long time. The engine does eventually run, or may start but immediately dies.

Preliminary Checks Make sure the engine’s operator is using the correct starting procedure.

Sensor Checks

Check the Engine Coolant Temperature sensor with the DST. Compare the engine coolant temperature with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 10 degrees greater or less than the ambient air temperature on a cold engine, check for high resistance in the coolant sensor circuit. Check the cam/crank sensors.

Check the Throttle Position (TPS) and Foot Pedal Position (FPP) sensor connections.

Fuel System Checks

Important: A closed LPG manual fuel shut off valve will create a no start condition. Check Venturi assembly for proper installation and leakage. Verify proper operation of the Shut-off solenoid Valves. Verify proper operation of the system low pressure Regulator. Check for air intake system leakage between the Throttle Body and Air

Filter Assembly. Check the fuel system pressures. Refer to the Fuel System Diagnosis.


NOTE: LPG requires higher secondary ignition system voltages for the equivalent gasoline operating conditions. Check for the proper ignition voltage output with J 26792 tool or the

equivalent. Verify that the spark plugs are the correct type and properly gapped. Check the spark plugs for the following conditions: Wet plugs (oil fouling). Cracks. Wear. Burned electrodes. Heavy deposits. Check for bare or shorted ignition wires. Check for moisture in the distributor cap. Check for loose ignition coil connections. Important: 1. If the engine starts but then immediately stalls, check the cam/crank sen-

sor. 2. Check for improper gap, debris or faulty connections.

41

Checks Action


Important: The LPG Fuel system is more sensitive to intake manifold lea-kage than the gasoline fuel supply system. Check for the following: Engine vacuum leaks Manifold vacuum leaks. Venturi Vacuum Leaks Improper valve timing-how? Low compression Improper valve clearance. Worn rocker arms Broken or weak valve springs Worn camshaft lobes.



ure. Check for possible plugged catalytic converter. Refer to Restricted Exhaust System Diagnosis.

42

CUTS OUT, MISSES

Checks Action DEFINITION: A surging or jerking that follows engine speed, usually more pronounced as the engine load increases, but normally felt below 1500 rpm. The exhaust has a steady spitting sound at low speed, or hard acceleration for the fuel starvation that can cause the engine to cut-out.

Preliminary Checks None


1. Start the engine. 2. Check for proper ignition output voltage with spark tester J 26792. 3. Check for a cylinder misfire. 4. Verify that the spark plugs are the correct type and properly gapped. Remove the spark plugs and check for the following conditions: Insulation cracks. Wear. Improper gap. Burned electrodes. Heavy deposits. Visually/Physically inspect the secondary ignition for the following: Ignition wires for arcing and proper routing. Cross-firing. Ignition coils for cracks or carbon tracking.


Perform a cylinder compression check. Check the engine for the following: Improper valve timing. Improper valve clearance. Worn rocker arms. Worn camshaft lobes. Broken or weak valve springs. Check the intake and exhaust manifold passages for casting flash.

Fuel System Checks

Check the fuel system: Plugged fuel filter (if equipped). Low fuel pressure, etc. Refer to Fuel System Diagnosis. Check the condition of the wiring to the Shut-off Valves.

Additional Check

Check for Electromagnetic Interference (EMI), which may cause a misfire con-dition. Using the DST, monitor the engine rpm and note sudden increases in rpm displayed on the scan tool but with little change in the actual engine rpm. If this condition exists, EMI may be present. Check the routing of the second-ary wires and the ground circuit.

43

HESITATION, SAG, STUMBLE

Checks Action DEFINITION: The engine has a momentary lack of response when accelerating the engine. The condi-tion can occur at any engine speed. The condition may cause the engine to stall if it’s severe enough. Preliminary Checks None.

Fuel System Checks

Check the fuel pressure. Refer to Fuel System Diagnosis. Check for low fuel pressure during a moderate or full throttle accelera-

tion. If the fuel pressure drops below specification, there is possibly a faulty low pressure regulator or a restriction in the fuel system.

Check the TMAP sensor response and accuracy. Check Shut-Off electrical connections. Check the Regulator, Venturi and Throttle body for proper installation

and leakage.


NOTE: Natural Gas and Propane require higher secondary ignition system voltages for the equivalent gasoline operating conditions. Check for the proper ignition voltage output with J 26792 or the equiva-

lent. Verify that the spark plugs are the correct type and properly gapped. Check for faulty spark plug wires. Check for oil fouled spark plugs.

Additional Check Check for manifold vacuum or air induction system leaks. Check the alternator output voltage.

44

BACKFIRE

Checks Action DEFINITION: The fuel ignites in the intake manifold, or in the exhaust system, making a loud popping noise.

Preliminary Check None.


NOTE: LPG requires higher secondary ignition system voltages for the equivalent gasoline operating conditions. Check for the proper ignition coil output voltage using the spark tester

J26792 or the equivalent. Check the spark plug wires by connecting an ohmmeter to the ends of

each wire in question. If the meter reads over 30,000 ohms, replace the wires.

Check the connection at ignition coil. Check for deteriorated spark plug wire insulation. Remove the plugs and inspect them for the following conditions: Wet plugs (oil fouling). Cracks. Wear. Improper gap. Burned electrodes. Heavy deposits.

Engine Mechanical Check

Important! The LPG Fuel system is more sensitive to intake manifold leakage than a gasoline fuel supply system. Check the engine for the following: Improper valve timing. Engine compression. Manifold vacuum leaks. Intake manifold gaskets. Sticking or leaking valves. Exhaust system leakage. Check the intake and exhaust system for casting flash or other restric-

tions. Fuel System Checks Perform a fuel system diagnosis. Refer to Fuel System Diagnosis.

45

LACK OF POWER, SLUGGISHNESS, OR SPONGINESS

Checks Action DEFINITION: The engine delivers less than expected power. There is little or no increase in speed when throttling the engine.

Preliminary Checks

Refer to the Fuel system OBD System Check. Compare the customer’s engine with a similar unit to verify customer has

an actual problem. Do not compare the power output of the engine op-erating on Natural Gas and Propane to one operating on gasoline as the fuels do have different performance characteristics.

Remove the air filter and check for dirt or restriction. Check the vehicle transmission. Refer to the OEM transmission diagnostics.

Fuel System Checks

Check for a restricted fuel filter, contaminated fuel, or improper fuel pres-sure. Refer to LPG Fuel System Diagnosis.

Check for the proper ignition output voltage with the spark tester J 26792 or the equivalent.

Check the Regulator and Throttle body for proper installation and lea-kage. Check all air inlet ducts for condition and proper installation.

Check all air inlet ducts for condition and proper installation. Check for fuel leaks in supply lines. Verify that the Fuel Supply Valve on the supply line is open. Verify that liquid fuel (not vapor) is being delivered to the Regulator.

Sensor Checks Check the Heated Exhaust Gas Oxygen Sensor (HEGO) for contamina-

tion and performance. Check for proper operation of the TMAP sensor. Check for proper operation of the TPS and FPP sensors.



ure. Check for possible plugged catalytic converter.

Engine Mechanical Check

Check the engine for the following: Engine compression. Valve timing. Improper or worn camshaft. Refer to Engine Mechanical in the Service Manual.

Additional Check

Check the ECM grounds for being clean, tight, and in their proper loca-tions.

Check the alternator output voltage. If all procedures have been completed and no malfunction has been found, review and inspect the following items: Visually and physically, inspect all electrical connections within the sus-

pected circuit and/or systems. Check the DST data.

46

POOR FUEL ECONOMY

Checks Action

DEFINITION: Fuel economy, as measured by refueling records, is noticeably lower than expected. Also, the economy is noticeably lower than it was on this vehicle at one time, as previously shown by refueling records.

Preliminary Checks

Check the air cleaner element (filter) for dirt or being plugged. Visually check the vacuum hoses for splits, kinks, and proper connec-

tions. Properly inflated tires. Check the operators driving habits for the following: Excessive idling or stop and go driving. Carrying of very heavy loads. Rapid acceleration. Suggest to the owner to fill the fuel tank and to recheck the fuel economy

and/or suggest that a different operator use the equipment and record the results.

Fuel System Checks Check the Regulator fuel pressure. Refer to Fuel System Diagnosis. Check the fuel system for leakage.

Sensor Checks Check the TMAP sensor.


Verify that the spark plugs are the correct type and properly gapped. Remove the plugs and inspect them for the following conditions: Wet plugs (oil fouling). Cracks. Wear. Improper gap. Burned electrodes. Heavy deposits. Check the ignition wires for the following items: Cracking. Hardness. Proper connections.

Cooling System Checks

Check the engine thermostat to see if it is stuck open or for the wrong heat range.

47

ROUGH, UNSTABLE, OR INCORRECT ENGINE SPEED, STALLING

Checks Action DEFINITION: The engine runs unevenly at under no load. If severe enough, the engine may shake. The engine speed may vary in rpm. Either condition may be severe enough to stall the engine.

Preliminary Check None.

Sensor Checks

Check the Heated Exhaust Gas Oxygen Sensor (HEGO) performance: Check for silicone contamination from fuel or improperly used sealant. If

contaminated, the sensor may have a white powdery coating result in a high but false signal voltage (rich exhaust indication). The ECM will reduce the amount of fuel delivered to the engine causing a severe performance prob-lem.

Check the Temperature Manifold Absolute Pressure (TMAP) sensor response and accuracy.

Fuel System Checks

Check for rich or lean symptom that causes the condition. Run the engine at the speed of the complaint. Monitoring the oxygen sensor will help identify the problem. Verify proper operation of the Regulator. Perform a cylinder compression test. Refer to Engine Mechanical in the

Service Manual. Check the Regulator fuel pressure. Refer to the Fuel System Diagnosis. Check the Regulator, Venturi and Throttle body for proper installation and

leakage.


Check for the proper ignition output voltage using the spark tester J26792 or the equivalent.

Verify that the spark plugs are the correct type and properly gapped. Remove the plugs and inspect them for the following conditions: Wet plugs (oil fouling). Cracks. Wear. Improper gap. Burned electrodes. Blistered insulators. Heavy deposits. Check the spark plug wires by connecting an ohmmeter to the ends of each wire in question. If the meter reads over 30,000 ohms, replace the wires.

Additional Checks

Important: The LPG Fuel system is more sensitive to intake manifold leakage than the gasoline fuel supply system.

Check for vacuum leaks. Vacuum leaks can cause poor engine perfor-

mance. Check the ECM grounds for being clean, tight, and in their proper locations.

Check the battery cables and ground straps. They should be clean and se-cure. Erratic voltage may cause all sensor readings to be skewed resulting in poor engine performance.

48

Checks Action

Engine Mechani-cal Check

Check the engine for: Broken motor mounts. Improper valve timing. Low compression. Improper valve clearance. Worn rocker arms. Broken or weak valve springs. Worn camshaft lobes.

49

SURGES/CHUGGLES

Checks Action DEFINITION: The engine has a power variation under a steady throttle. The engine feels as if it speeds up and slows down with no change to the throttle.

Preliminary Checks None.

Sensor Checks Check the Heated Exhaust Gas Oxygen Sensor (HEGO) performance.

Fuel System Checks

Check for Rich or Lean symptom that causes the condition. Run the engine at the speed of the complaint. Monitoring the oxygen sen-

sor will help identify the problem. Check the fuel pressure while the condition exists. Refer to Fuel System

Diagnosis. Verify proper fuel control solenoid operation. Verify that the LPG manual shut-off valve is fully open. Check the in-line fuel filter for restrictions.


Check for the proper ignition output voltage using the spark tester J26792 or the equivalent.

Verify that the spark plugs are the correct type and properly gapped. Remove the plugs and inspect them for the following conditions: Wet plugs (oil fouling). Cracks. Wear. Improper gap. Burned electrodes. Heavy deposits. Check the Crankshaft Position (CKP) sensor.

Additional Check

Check the ECM grounds for being clean, tight, and in their proper locations. Check the alternator output voltage. Check the vacuum hoses for kinks or leaks. Check Transmission

50

CRANKCASE VENTILATION SYSTEM INSPECTION/DIAGNOSIS RESULTS OF INCORRECT OPERATION

A plugged positive crankcase ventilation (PCV) orifice or hose may cause the following conditions: Rough or unstable engine speed Stalling or low idle speed Oil leaks Oil in the air cleaner Sludge in the engine A leaking PCV orifice or hose may cause the following problems: Rough or unstable engine speed. Stalling High idle speed Functional check: Any blow-by in excess of the system capacity, from a badly worn engine, sustained heavy load, etc., is exhausted into the air cleaner and is drawn back into the engine. Proper operation of the crankcase ventilation system depends on a sealed engine. If irregular oil flow or dilution is noted and the crankcase ventilation system is functioning properly, check the engine for another possible cause. Correct any of these problems first. If an engine is idling rough, inspect for a clogged PCV orifice, a dirty vent filter, air cleaner element, or plugged hose. Replace any faulty items found. Use the following procedure: Remove the PCV hose (positive side) from the rocker arm cover. Operate the engine at idle. Place your thumb over the end of the hose in order to check for vacuum. If there is no vacuum at the hose end,

inspect for the following items:

Plugged hoses The manifold vacuum port

Turn the engine OFF. Inspect the PCV orifice in the valve cover for debris or blockage.

51

Electrical Section

53

DST (Diagnostic Scan Tool)

54

DST (Diagnostic Scan Tool) Software Installation Instructions

Installation of the USB to CAN adapter driver and utility. Installation of the Spectrum series IV DST software program. Software login and password functionality.

DST INSTALLATION INSTRUCTIONS Before installing the DST software, please be sure your computer meets the minimum system re-quirements. Supported operating systems are: Windows 7 (32 bit) Windows Vista (32 bit) Windows XP (32 bit) Minimum processor speed: Pentium III 1.0 GHz

Minimum RAM requirement: Windows 7 1 GB Windows Vista 512 MB Windows XP 256 MB Additional: Display capable of at least 1024 x 768 screen resolution and one available USB port.

Examples and snapshots used in this manual are based off of the initial DST tool release as of Au-gust, 2011 using the Windows 7 operating system. This tool is used for multiple fuel systems and is frequently updated. Snapshot illustrations may vary depending on the installed operating system and changes included in any updated DST display Interface. This software has the ability to auto-matically detect functions that may or may not be used in any one particular fuel system. In this instance unused or irrelevant values and graphic displays will be shaded in gray on the DST display screens. Terms, names and descriptions of systems and other servicing procedures may be up-dated periodically with new DST installation software.

55

Ifak Driver and Utility Installation:

NOTE: Close any open applications prior to installing the DST.

Insert the Ifak CD included with your USB to CAN adapter and open the file folder.

For users with restricted rights using Windows 7 or Windows Vista, select Run as administrator as shown above. For all others, select the Setup file. You may receive a Windows message asking you to confirm the installation request by an unknown publisher. You must select Yes to continue the installation.

56

Select the Next box to continue with the installation.

Enter your company name or organization and click the Next box. Follow the next steps using the recommended defaults.

57

Click the Finish box to complete the installation. It is now recommended you re-boot your computer.

Connect the Ifak adapter to an available USB port. You may see a message confirming you wish to make changes to the computer from an unknown publisher. If so, you must select the Yes box to continue the installation. Win-dows will now install the Ifak driver to your computer. You should see a message confirming the driver was successfully installed as shown above.

58

Open the Start menu. You should see the is CAN Configuration utility confirming the utility installation. Select the is CAN Configurator.

Click the Add box.

59

Select the USB button, then click the OK box.

Click on the Search attached device box.

60

When the Ifak device serial number is shown, click the Select box, then click the OK box. The Ifak driver and utility installation is now complete. If you had problems during this installation please see the additional information and test instructions for your Ifak adapter included with your service test kit.

61

Spectrum Series IV DST Software Installation:

In most instances the OEM manufacturer will have supplied you the DST software installation files. The instal-lation files may have been provided to you by internet download, CD or other media storage. Regardless of the delivery system, please follow the instructions to install the DST software below. If the files were supplied to you in a .zip file format it is strongly recommended that the files are first unzipped before proceeding with the DST soft-ware installation.

Insert the CD, USB flash drive, other storage media or find the location where the DST software has been saved on your computer.

Open the Spectrum_Series_IV_DST file folder.

62

For users with restricted rights using Windows 7 or Windows Vista, it may be necessary to select the Run as administrator box similar to the Ifak USB driver installation. For all others, click the Spectrum Engine Moni-tor.msi file. You may receive a Windows message asking you to confirm the installation request by an unknown publisher. If so, you must select the Yes box to continue the installation.

Click the Next box.

63

Follow the on screen prompts that will guide you through the installation.

The Spectrum 4 logo shortcut is placed on the desktop confirming the installation is complete. It is now recom-mended that you re-boot your computer.

64

Connecting the DST:

Connect the Diagnostic Link Connector or DLC to the Ifak adapter’s connector. Connect the other end of the DLC connector to the engine harness (3 pin connector).

Click on the Spectrum 4 shortcut to open the DST software program. Turn the engine ignition power ON.

65

Click on the S3000 tab at the lower left of the Spectrum Engine Monitor page.

On the S3000 data stream page, pull down the Settings menu and click on Connection Settings

66

The Select CAN Device & Channel dialog box will appear. Select the Ifak device, and then click the OK box.

Under the Connection drop down menu, select Connect

67

When connected, the live data stream appears in the Value column.

68

Using the Spectrum DST

The Spectrum IV DST is the next generation all CAN (Controller Area Network) enabled diagnostic tool. This is a new tool for emission year 2011. It is designed to be compatible for all 2011 Spectrum fuel systems that use both the MEFI (industrial) and S3000 (mobile) ECM applications. The DST operates on an expandable platform and its functions are planned to increase in the future. The functions are listed below: Updating the ECM calibration using the .s37 calibration file. Provide graphical display interface for engine and sensors parameters Display DTC (Diagnostic Trouble Codes) Provide data stream information from engine sensors and actuators Plot data. Record Data

69

Updating the ECM Calibration

In field updates (or reflashing) are possible with the S3000 ECM using the DST. Always check first to be sure the ECM has been programmed with the latest calibration before attempting any diagnostic or service repair proce-dure. Calibration files are supplied in the .s37 file format. These files may be supplied to you by the OEM along with a password unique to that particular s.37 file. You will need the password to complete the re-programming procedure. Before re-programming the ECM, shut down any other programs running on your PC including wireless and e-mail programs. The PC must be dedicated to the re-programming process at this time. Be sure your PC bat-tery is adequately charged. Failure to follow these instructions may render the ECM not usable in the field.

Under the Tools drop down menu, select Reprogram S3000 Engine Control Unit. Turn ignition power ON.

The S3000 Flash Upgrade Wizard dialog box will appear. Select the Next box.

70

Use the Browse box to navigate to the location of the calibration file.

Enter the password that was supplied with the calibration file.

71

Select the Next box.

The progress bar shows the status updating.

Any interruption during the re-programming process may render the ECM unusable in the field.

72

Please wait until you receive a message confirming the update is complete.

Turn the ignition power OFF. Wait 10 seconds and select Finish.

Turn the ignition ON. Verify the calibration updated with the new file number in the ECM Part Number data stream shown above. The reprogramming process is now complete.

73

Graphic Display Interface

Shown as the monitor page in the DST, the above page is the default entry page that opens with the DST pro-

gram. It provides a graphical interface for important engine parameters. Graphics shown in gray are not available for the specific application the DST may be connected to as shown above. This function is controlled by the ECM calibration file and cannot be changed by the service technician.

74

Display DTC (Diagnostic Trouble Codes)

DTC codes can be read by clicking on the Diagnostics tab at the bottom of the monitor page. The source of the DTC stream can be set manually for the MEFI ECM or the S3000 ECM, or left in the default All position for auto detection of the DTC codes from either MEFI or the S3000 ECM. Codes that can be viewed are set in two catego-ries, active and historic. Active codes are codes that are set and the fault that is causing the code to set is constant. Historic codes are codes that have set in the past, but the fault that caused them has been corrected such as with an intermittent problem. This function is selectable by choosing the Active or Historic, as shown in the above image. Codes can be cleared by clicking the Clear box. The DTC set code list may also be saved by clicking the Save box shown above. The file will be saved in a convenient HTML file compatible with Windows In-ternet Explorer and will provide a browse function to save the file to a location of choice for the service technician.

75

Data Stream:

The fuel and emissions service manual will refer to the DST and asked that it be connected in the data stream mode. This simply means it is first connected and that data is shown on the S3000 data stream page as shown above. The data stream page can be accessed by selecting the S3000 tab shown at the lower left above.

Plot Data:

Data stream information may also be selected for a trace plot. This page is available by clicking the Plot tab at the lower page center as shown above.

76

The custom parameters of the plot can be selected by clicking on the plot icon just below the Settings menu item at the top left of the page shown above. To save the custom settings select OK.

77

Diagnosing Intermittent Problems

Intermittent fuel system problems can prove to be the most challenging to diagnose. It is of the upmost important when diagnosing intermittent problems to operate the engine system while monitoring with the DST and pressure gauge set. An example of this would be if the DST showed a lean fuel mixture at full load. One of the first things to look at would be the fuel pressure. The fuel pressure would need to be mo-nitored while the engine is operating at full load, not at low or no load because the leaning effect does not occur until full load. Electrical problems should be treated in a similar same way. One excellent tool for finding intermittent electrical problems is the DST plot function. Set up the plot for the sensor code that sets. An example of this would be if an intermittent IAT code set, tag the IAT voltage and watch the plot. While watching the plot, agitate the electrical wire connection at the sensor and ECM connector. The reso-lution of the plot screen is such that you will be able to see any unstable voltages that you may not see with a standard DVOM.

Caution should be used when pressure washing the under hood of any electrical system. Avoid direct

pressure spray on the system electrical connectors. The connectors are splash proof but if high pressure water or steam is sprayed directly at the connector moisture can become trapped behind the connector seal and cause serious system problems, many of them showing up as intermittents. Extra care must be taken when probing electrical pins and terminals. Do not bend or spread these terminals as this can also be a source of intermittent problems cause by improper handling of these low voltage connectors and ter-minals. When running electrical diagnostics avoid back probing the wire connectors as this may damage the wire seal. When running the continuity checks use a wire probe to only touch the wire terminal. Forc-ing the electrical probe into the terminal may cause the terminal to spread leading to permanent damage. More Intermittent diagnostic information can be found on the Fuel Symptom Diagnostics, Intermittent Diag-nostic Charts.

Fuel System Checks This system has OBD (Onboard Diagnostics) for many sensors, relays and monitors, but not all mal-

functions have a DTC code available to alert the service technician to a problem. A good example of this would be the engine ignition system. If a spark plug, cap, rotor or wire fails a DTC code may not be set. The DST provides advanced diagnostic capabilities, but some items are still left to the basics of general engine mechanics. Following the recommended maintenance schedule is the best way to prevent this type of problem for which a DTC code does not exist. Many times the basics are overlooked and can be attri-buted to improper maintenance. Some general rules to follow are: Check to be sure the ECM is programmed with the latest calibration file Check general engine tune up items such as spark plugs, distributor cap and rotor, spark plug wires,

air, and fuel filters if equipped with such. Check that the charging system is working correctly. Check block heaters, battery heaters, battery terminals and fuel supply systems for proper operation.

79

INTERMITTENT PROBLEMS Intermittent fuel system problems can prove to be the most challenging to repair. It is most important to remember when looking to find the cause of these problems, to operate the system in the condition when and where the problem occurs. An example of this would be, if the DST showed a lean fuel mixture at full load, one of the first things to look at would be the fuel pressure. The fuel pressure would need to be monitored while the machine is operating at full load, not at idle because the leaning effect does not oc-cur at idle. Electrical problems should be treated the same way. One excellent tool for finding intermittent electrical problems is the DST plot/log function. Set up the plot for the code that sets. An ex-ample of this would be if an intermittent IAT code set, tag the IAT voltage and watch the plot. While watching the plot, agitate the electrical wire connection at the sensor and ECM connector. The resolution of the plot screen is such that you will be able to see any unstable voltages that you would otherwise not see with a standard DVOM. Caution should be used when pressure washing the under hood of any electrical system. Avoid direct pressure spray on the system electrical connectors. They are splash proof, but if water is sprayed direct-ly at the connector moisture can become trapped behind the connector seal and cause serious system problems. Extra care must be taken when probing electrical pins and terminals. Do not bend or spread these ter-minals as this can also be a source of intermittent problems cause by improper handling of these connectors.

81

Engine Wire Schematic

82

2011 3.0L GM Engine IMPCO Emission Certified LPG Fuel System

85

Engine Wire Harness Repair

86

ON-VEHICLE SERVICE WIRE HARNESS REPAIR

The ECM harness electrically connects the ECM to a various components in both the en-gine and passenger compartments. Wire harnesses should be replaced with proper part number harnesses. When wires are spliced into a harness, use wire with high temperature insulation only. Low current and voltage levels are used in the system, so it is important that the best possible bond at all wire splices be made by soldering the splices.

CONNECTORS AND TERMINALS Use care when probing a connector or replacing terminals in them to prevent shorting opposite terminals and damage certain components. Al-ways use jumper wires between connectors, for circuit checking. Do not probe through the Weather-Pack seals with oversized wire probes. Use tachometer adapter J 35812 (or equivalent) which provides an easy hook up of the tach lead. The connector test adapter kit J 35616 (or equivalent), contains an assortment of flexible connectors used to probe terminals during diag-nosis. Fuse remover and test tool BT 8616, or equivalent, is used for removing a fuse and to adapt fuse holder, with a meter, for diagnosis. Do not solder oxygen sensor wire terminals as these wire ends are used for the sensors oxygen reference. Open circuits are often difficult to locate by sight due to dirt, oxidation, or terminal misalignment. Merely wiggling a connector on a sensor, or in the wiring harness, may correct the open circuit condition. This should always be considered, when an open circuit, or failed sensor is indi-cated. Intermittent problems may also be caused by oxidized or loose connections. Before making a connector repair, be certain of the type of connector. Weather-Pack and Com-pact Three connectors look similar, but are serviced differently.

REPAIRING TWISTED/SHIELDED CABLE

1. Remove outer jacket

2. Unwrap aluminum/Mylar tape. Do not re-move Mylar.

3. Untwist conductors, strip insulation as ne-cessary.

4. Splice wire using splice clips and rosin core solder. Wrap each splice to insulate.

5. Wrap with Mylar and drain wire (uninsu-lated) wire.

6. Tape over entire juncture and secure.

87

REPAIRING TWISTED LEADS

1. Locate Damaged Wire.

2. Remove insulation as required.

3. Splice two wires together suing splice clips and rosin core solder.

4. Cover splice with tape to insulated from other wires.

5. Retwist as before and tape with electrical tape and hold in place.

MICRO-PACK

Refer to Figure 2 and repair procedure for re-placement of a Micro-Pack terminal.

Micropack Connector

1. Cable 2. Terminal 3. Locking Tang 4. Tool J33095/BT8234-A

METRI-PACK Some connectors use terminals called Metri-Pack Series 150. They are also called “Pull-To-Seat” terminals because of the method of instal-lation. The wire is inserted through the seal and connector, the terminal is crimped on the wire and then pulled back into the connector to seat it in place.

Metri-Pack Series 150 Terminal Removal

1. Slide the seal back on the wire. 2. Insert tool BT-8518, or J 35689, or equiva-

lent, as shown in insert “A” and “B” to release the terminal locking tab (2).

3. Push the wire and terminal out through the connector. If reusing the terminal, reshape the locking tab (2).

WEATHER-PACK

A Weather-Pack connector can be identified by a rubber seal, at the rear of the connector. The connector is used in the engine compartment to protect against moisture and dirt that may oxid-ize and/or corrode the terminals. Given the low voltage and current levels found in the electronic system, this protection is necessary to ensure a good connection.

88

WEATHER-PACK TERMINAL REPAIR

1. Open secondary lock hinge on connector.

2. Remove terminal using tool.

3. Cut wire immediately behind cable seal

4. Replace terminal. a. Slip new seal onto wire b. Strip 5 mm (.2”) of insulation from wire. c. Crimp terminal over wire and seal.

5. Push terminal and connector and engage locking tangs.

6. Close secondary lock hinge.

Use tool J M28742, or BT8234-A or equivalent to remove the pin and sleeve terminals. If the re-moval is attempted with an ordinary pick, there is a good chance that the terminal will be bent, or deformed. Unlike standard blade type terminals, these terminals cannot be straightened once they are bent. Verify that the connectors are properly seated and all of the sealing rings in place, when con-necting leads. The hinge type flap provides a

backup, or secondary locking feature for the connector. They are used to improve the con-nector reliability by retaining the terminals, if the small terminal lock tabs are not positioned prop-erly. Weather-Pack connections cannot be replaced with standard connections. Additional instruc-tions are provided with Weather-Pack connector and terminal packages.

89

Diagnostic Trouble Codes (DTCs)

90

Ignition Control System Diagnostics

Before using the Ignition Control Diagnostic chart be sure to check the following items: Spark plug wires: Be sure spark plug wires are in good condition. Check for cuts, breaks, burns, hardness or swelling. LPG fuel requires much higher peak firing voltages compared to gasoline. Check spark plug electrical continuity using a DVOM. Wires should ohm out to no more than 1,000 ohms per foot of wire length. Distributor cap and rotor: Check the cap and rotor assembly for moisture, corrosion or carbon tracking. The ignition timing is not adjustable. Turning the distributor assembly will not change the ignition timing, but will alter the rotor phase. Wipe away dust and debris from the ignition coil tower. System power fuses: Check the system power fuses. These sources supply the ignition coil and module system power. Check that the power and ground terminals are clean and in the proper location.

91

Ignition Control System Diagnostic Chart Step Action Value(s) Yes No

1 Did you perform the On-Board (OBD) System Check? -

Go to Step (2)

Go to OBD Sys-tem Check

Section

2

DST connected and in the system data mode. Crank the engine and observe the engine

speed signal on the DST

Is the value greater than the specified value?

~125 RPM Go to Step

(5) Go to Step (3)

3

Check the DST for historical code sets. (Always diagnose and repair codes with the lowest numerical value first).

Did you find and correct the problem?

Go to Step

(16) Go to Step (4)

4 Run the diagnostic chart for DTC 522752 Did you find and correct the problem?

Go to Step

(16) Go to Step (5)

5

Disconnect the ignition module connector C035

Using an LED type test lamp check for a sig-nal between the ignition module connector pin B and battery positive

Crank the engine

Does the LED test lamp flash while cranking the engine?

Go to Step(6) Go to Step (10)

6

Using a DVOM check for power between the ignition module connector pin A and engine ground

Do you have power?

System vol-tage

Go to Step (7)

Repair the sys-tem power

circuit. Check all system fuses and power relay

connections

7

Disconnect the ignition coil connector C035 Using a digital LED test lamp check for a sig-

nal between the ignition coil connector pin B and battery positive

Crank the engine

Does the LED test lamp flash while cranking the engine?

Go to Step

(8) Go to Step (13)

8

Using a DVOM check for voltage between the ignition coil connector pin A and engine ground

Does the DVOM show voltage?

System vol-tage

Go to Step (9)

Repair the sys-tem power

circuit. Check all system fuses and power relay

connections

9 Replace the ignition coil

Is the replacement complete?

Go to Step

(16) _

92


10

Key OFF Disconnect the connector ECU-C Using a DVOM check for continuity between

ignition module connector pin B and ECM connector pin K1

Do you have continuity between them?

Go to Step

(11)

Repair the open ignition control circuit. See wir-

ing harness repair section.

11

Using a DVOM check for continuity between ignition module connector pin B and engine ground

Do you have continuity between them?

Repair the shorted to

ground igni-tion control circuit. See

wiring harness repair section.

Go to Step (12)

12 Replace ECM


Go to Step

(16) -

13

Disconnect coil. Using a DVOM check for continuity between the ignition module con-nector pin C and engine ground

Do you have continuity?

Go to Step

(14)

Repair the open ignition module ground circuit. See wiring har-

ness repair.

14

Using a DVOM check for continuity between the ignition module connector pin D and igni-tion coil connector pin B


Go to Step

(15)

Repair the open ignition module circuit. See wir-

ing harness repair.

15 Replace the ignition module. Is the replacement complete?

Go to Step

(16) -

16

Remove all test equipment except the DST. Connect any disconnected components, fus-

es, etc. Using the DST clear DTC information from

the ECM. Turn the ignition OFF and wait 30 seconds. Start the engine and operate the vehicle to

full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine check for any

stored codes. Does the engine operate normally with no stored codes?

System OK Go to OBD Sys-

tem Check

94

DTC 51 ETC TPS 1 Range

Conditions for Setting the DTC Electronic Throttle Control Check Condition-Ignition ON Fault Condition-TPS 1 voltage below 0.2 TPS 2 voltage greater than 4.95 MIL-On during active fault

Circuit Description The electronic throttle body has two throttle position sensors TPS1 and TPS2. The voltage from these sensors is used to determine the percentage throttle opening. The TPS sensors have a nominal output range of 0.2 to 4.95 volts. From the throttle body itself TPS1 ranges from 0.2 to 4.95 volts as the throttle is opened, TPS2 ranges from 4.95 to 0.2 volts for this same closed to open travel. The ECM rectifies TPS2 signal so both signals on the diagnostic monitor read from 0.2 to 4.95 as the throttle is opened. The travel of the throttle plate from the fully closed to the fully open mechanical stops may not use this entire range of voltages. The ECM learns the actual range of voltages used and adjusts the THROTTLE POSITION read-ing to range from 0 to 100% over this used range of voltages. The system looks at both TPS signals and if the readings are outside of the upper and lower limits or do not agree with each within limits a code will be set. The following failure combinations and resulting outcomes are possible: a) TPS1 fails open or shorted: MIL illuminated, ECM uses TPS2, normal engine operation b) TPS2 fails open or shorted: MIL illuminated, ECM uses TPS1, normal engine operation c) TPS1 & 2 fail open or shorted: MIL illuminated, ECM stops controlling throttle, throttle goes to limp

home position and is non- responsive, engine will high idle or allow truck to move slowly. d) TPS1 & 2 do not match: MIL illuminated, ECM will use the higher of the two TPS readings resulting in

normal or less than normal engine power.

95

Typical TPS and Throttle Position Readings (assumes 5.00 supply voltage):

Actual Throttle Position

TPS1 reading at Throttle


TPS1 reading

on Moni-tor

TPS2 reading

on Moni-tor

Throttle Position on Moni-

tor Fully

closed 0.32 4.70 0.32 0.30 0

¼ Open 1.32 3.70 1.32 1.30 25 ¾ Open 3.32 1.70 3.32 3.30 75

Fully Open 4.32 0.70 4.32 4.30 100 CONDITIONS FOR SETTING THE DTC DTC 51 will set if TPS1 and TPS2 disagree by greater than 5.96% A short circuit code will set if the TPS1 (as shown on the diagnostic monitor) is greater than 99.02%

of the 5 Volt Power Supply 1 (approx. 4.95 volts) A short circuit code will set if the TPS2 (as shown on the diagnostic monitor) is greater than 99.8% of

the 5 Volt Power Supply 1 (approx. 4.99 volts) An open circuit code will set if the TPS1 (as shown on the diagnostic monitor) is less than 4% of the 5

Volt Power Supply 1 (approx. 0.2 volts) An open circuit code will set if the TPS2 (as shown on the diagnostic monitor) is less than 4% of the 5

Volt Power Supply 1 (approx. 0.2 volts)

96



1

Did you perform the On-board diagnostics (OBD) system check?

NOTE: If the 5 volt reference Supply 1 is shorted to ground, various codes may set, including Throttle, Pedal 1, Oil Pressure, Cam and 5 Volt Power Supply Codes. If multiple codes are set, refer to diagnostics for codes 524261 to verify 5 volt reference.

Go to Step

(2)

Go to On-Board Diag-

nostics System

Check/Malfunction indicator

lamp.

2

With the monitor connected, Key ON, read both throttle position sensors 1 and 2 voltag-es.

Is either reading below 0.2 volts Is the TPS 1 voltage above 9.95 volts or is

TPS 2 voltage above 4.99

Is the higher voltage minus the lower voltage di-vided by 5 then multiplied by 100 greater than 6. NOTE: this is the formula the ECU uses to de-termine if the TPS readings are within the specifications

TPS 1 <0.2V TPS 2 >4.99V

Go to Step (3)

Intermittent problem. Go

to Preliminary and Intermit-tent Checks

3

Key OFF, disconnect C017 from the throttle body.

Key ON, measure the voltage from C017 pin 6 to pin 2

Is the voltage between 4.8 and 5.2 volts?

Between 4.8-5.2V

Go to Step (5)

Go to Step (4)

4

Key OFF, disconnect ECU-B Measure the resistance from C017 pin 2 to

ECU B pin G2 Measure the resistance from C017 pin 6 to

ECU B pin G4 Is the resistance less than 5Ω?

NOTE: Do not probe wires without proper ser-vice tool. Permanent harness damage may result.

Verify that there are no codes for the 5 volt supply before pro-

ceeding. Replace the ECU. Go to

Step (9)

Repair the circuit as ne-

cessary. Refer to Wire Har-ness Repair.

Go to Step (9)

97


5

With C017 disconnected, measure the resis-tance from pin 6 to pin 1 of the throttle body.

Push the throttle plate to the fully closed posi-tion, and then observe the resistance sweep while moving the throttle to the fully open position

Repeat the test across pin 6 to pin 4. Is the resistance change smooth with no ob-served glitches, and does the resistance vary from 800 to 1500Ω for pin 6 to 1 and from 1400 to 300 for pin 6 to 4 as the throttle is moved from fully closed to fully open?

Go to Step

(6)

Replace the throttle body

assembly. Go to Step (7)

6


ECU-B pin G3 Measure the resistance from C017 pin 4 to

ECU-B pin D3 Is the resistance less than 5Ω?

<5 Ω

NOTE: Verify that there are no codes for

the 5 volt supply before proceeding. Replace the ECU. Got to

step 7


cessary. Refer to Wire Har-ness Repair. Go to Step

(7).

7

Remove all test equipment except the moni-tor.

Using the monitor, reset the adaptive learn. Connect any disconnected components, fus-

es, etc. Using the monitor, clear DTC information

from the ECM. Turn the ignition OFF and wait 30 seconds. Start the engine and operate the vehicle to

full operating temperature. Observe the MIL. Observe engine performance and driveability. After operating the engine within the test pa-

rameters of code, check for any stored codes.

Does the engine operate normally with no stored codes?

System OK.

Go to On-Board Diagnostics

System Check/Malfuncti

on Indicator lamp.

98


Conditions for Setting the DTC

Pedal Position Voltage Table Code Definition Condition Limit Comment

91-2 Pedal Sensor 1 to Pedal Sensor 2

Coherence Differ by more

Then 12 to 25 %

Varies with Pedal Position

522712-3 Pedal Sensor 1 Short to Ground Less then 0.09 volts 522712-4 Pedal Sensor 1 Short to High Greater Then 4.97 volts 522713-3 Pedal Sensor 2 Short to Ground Less then 0.09 volts

5227132-4 Pedal Sensor 2 Short to High Greater Then 2.49 volts

Circuit Description There are two pedal position sensors on the electronic foot pedal to signal to the ECU exactly how much throttle the driver has requested. The sensors are Hall Effect type not variable resistance sensors. The two sensors are provided as a safety feature in case one sensor fails. While the system looks at both sensors, sensor 1 is used to operate the system. The diagnostic tool allows the technician to monitor three signals which relate to the foot pedal. The first is pedal position, the system automatically scales the full travel of the pedal to equal 0 to 100 percent pedal position. The second and third signals are sensor 1 and sensor 2 voltages. Sensor 1 voltage can range from 0.66 to 4.95 volts but will usually be in the range of 1.0 to 3.6 volts. Sensor 2 voltage can range from 0.33 to 2.48 volts but will usually be in the range of 0.5 to 1.8 volts. (Sensor 2 should read ½ of sensor 1).

99



1


Go to Step (2).

Go to On-Board

Diagnostics System Check/

Malfunction indicator

lamp.

2

With the monitor connected, Key ON, read both pedal position sensor voltages.

See Pedal Position Voltage Table Slowly depress the pedal while observing the

monitor Are the readings within the specifications and is the sweep smooth without any glitches?


to Preliminary and Intermit-tent Checks.

If there is a glitch in the sweep, re-place the

pedal position sensor. Oth-erwise, go to

Step (3).

3

Check pedal position sensor Disconnect VIC 1 Key ON, measure voltage from VIC 1 pins S

and R. Key ON, measure voltage from VIC 1 pins M

and L. Is the voltage between 4.8 and 5.2 volts?

Go to Step (5)

Go to Step (4)

4

Key ON, measure the voltage from VIC 1 pins S and M to ground


Between 4.8 and 5.2V

Refer to the vehicle wiring diagram and check ground back to ECU, repair as ne-

cessary.

Refer to the vehicle wiring diagram and

repair the power supply problem be-tween here and ECU. Check for

possible ECU 5 volt prob-

lem. Refer to codes 524260 and 524261

for diagnostic aids.

100


5

Check pedal sensor Key OFF, disconnect VIC 1. Remove pins K

and J from the connector. Reconnect VIC 1. Key ON. Measure the voltage from each wire to en-

gine ground while slowly depressing the pedal.

Sweep, watch for glitch Repeat on other side NOTE: Pin J will show ½ the voltage of pin K. This is normal operation Does the voltage sweep with no glitches from greater than 0.09 volts to less than 4.97 volts on pin A and from greater than 0.09 to less than 2.49 volts on pin B?


>0.09 and <4.97 V

Reinstall the pins to the

proper posi-tions in the connector.

Go to step 6



Replace pedal position sen-

sor. Go to step 8.

6

Key OFF, disconnect ECU-A Measure the resistance from VIC 1 pin K to

ECU-A pin H2 and VIC 1 pin J to ECU-A pin F3.

Is the resistance less than 5Ω?

<5Ω Go to Step

(7)

Repair the open in the harness. Go to Step (8)

7

Connect the ECU-A and VIC 1 connectors. With the monitor or DST connected, wiggle the ECU-A connector.

Are any glitches observed while wiggling the connector?

Repair or re-place the

harness. Go to Step (8)

Replace the ECU. Go to

Step (8).

102

DTC 100 Oil Pressure Low/High/High at Stall

Conditions for Setting the DTC The normal voltage output limits for this sensor are 0.5 volts to 4.5 volts. If at any time, the voltage output is less than 0.46 volts or greater than 4.54 volts a DTC will be triggered. If the engine is not rotating the oil pressure should not raise above 0 psig. Due to the nature of this sensor an open ground wire with Key ON engine off may result in the signal voltage drifting up above 1 volt even at 0 psig oil pressure. To sense this fault a diagnostic is triggered if at an engine speed of 0 rpm the sensor voltage is above 1.0 volts.

Circuit Description The engine has an internal oil pump which creates oil pressure once the engine is rotating. An oil pressure sensor monitors the pressure created by this oil pump.

103

DTC 100 Oil Pressure Low/High/High at Stall Step Action Value(s) Yes No

1

Did you perform the On-Board (OBD) System Check?

- Go to Step

(2)

Go to OBD System.

Check Sec-tion

2

Verify that the engine has oil pressure using a mechanical oil pressure gauge before proceed-ing with this chart. Oil pressure must remain above 6 psi. Does the engine have oil pressure above 6 psi?

6 PSI Go to Step

(3) Repair faulty

Oiling System

3

Ignition ON, Engine Running DST connected in system Data Mode

Clear DTC 100 Warm the engine by idling until the ECT

temperature is above 160 degrees F. and has been running for at least one minute

Increase engine speed above 500 RPM Does DTC 100 reset?

Go to Step

(4)

Intermittent problem. Go to Intermittent

section

4

Clear DTC 100 Key OFF Disconnect oil pressure switch connector

C012 and isolate the connector from engine ground.

Start and run the engine Does DTC 100 reset?

Go to Step

(6) Go to Step

(5)

5 Replace oil pressure switch


Go to Step

(9) -

6

Ignition OFF Disconnect C012 Using a DVOM check for continuity between

the oil pressure switch connector and engine ground

Does the DVOM show continuity?

Repair the shorted to ground oil

pressure cir-cuit as

necessary. Refer to Wir-ing Repairs.

Go to Step (7)

7

Inspect ECU-B connector pin C1 for damage corrosion or contamination Did you find a problem?


cessary. Refer to Wir-ing Repairs in Engine Elec-

trical.

Go to Step (8)

104


8 Replace ECM Is the replacement complete?

Go to Step

(9) -

9



the ECM. Turn the ignition OFF and wait 30 seconds. Start the engine and run to full operating

temperature Observe the MIL Observe engine performance After operating the engine within the test pa-

rameters of DTC 100 check for any stored codes.


System OK Go to OBD

System Check

106

DTC 105 MAT Short to High/Ground/Open

Conditions for Setting the DTC Key ON Manifold Air Temp Short Circuit to High, MAT voltage greater than 4.95 V. Manifold Air Temp Short Circuit to Ground, MAT voltage less than 0.05 V Manifold Air Temp Open Circuit, MAT voltage greater than 4.88V but less than 4.94V

Circuit Description The TMAP is a combined manifold air temperature (MAT) and manifold absolute pressure (MAP) sensor. A temperature-sensitive resistor is used in the TMAP Sensor located in the intake manifold of the engine. It is used to monitor incoming air temperature and pressure; and the output, in conjunction with other sensors, is used to determine the airflow to the engine. The ECU provides a voltage divider circuit so that when the air is cool, the signal reads higher voltage, and lower when warm.

107

DTC 105 MAT Short to High/Ground/Open


1


NOTE: If the 5 volt reference supply 2 is shorted to ground, various codes may set, including Pedal 2, and 5 Volt Power Supply Codes, as well as ignition system malfunctions. If multiple codes are set, refer to diagnostics for code 524260 to verify 5 volt reference.

Go to Step

(2) Perform OBD System check

2

Key ON. Monitor MAT PID.

Does Monitor display MAT at the default value of 214 degrees?

Go to Step

(3)



3

Key OFF. Disconnect the TMAP sensor connector J8

from the TMAP sensor. •Key ON, measure the voltage across pins 1

and 2 Is the voltage between 4.8 and 5.2 volts? NOTE: Do not probe wires without proper ser-vice tool. Permanent harness damage may result

Between 4.8 and 5.2V

Go to Step (4)

Go to Step (5). If the 5

volt supply 2 is grounded,

an open code will be set.

4

Key OFF. Measure the resistance across the TMAP

sensor pins 1 and 2. Is the resistance correct for the temperature as shown in the temperature/ resistance chart above?


step last

Replace the TMAP sen-sor. Go to step last

5

Key OFF. Disconnect the ECU wire harness connector

ECU-B. Measure the resistance from TMAP sensor

connector C011 pin 2 and ECU-B pin E2. Measure the resistance from TMAP sensor

connector pin 1 and ECU-B pin H4. Is the resistance less than 5Ω?

<5Ω Go to Step

(6)


cessary

6

Disconnect the ECU wire harness connector. Measure the resistance between TMAP sen-

sor connector ground circuit pins 1 and 2. Is the resistance greater than 30MΩ?

>30MΩ Repair short circuit as ne-

cessary

Go to Step (7)

108


7

Recheck wire harness and TMAP sensor connectors for damage corrosion or contami-nation.

Were any problems found?

Repair the

circuit as ne-cessary

Go to Step (8)

8 Replace the ECU. Is the replacement complete?

Go to Step

(9)

110

DTC 106 MAP/Low/High/Short/Open


Key ON, engine RPM equals zero MAP reading less than 50 kPa absolute or greater than 108 kPa absolute MAP sensor signal voltage greater than 4.923 volts. MAP sensor signal voltage less than 0.122 volts. On successful engine start-up MAP value does not drop at least 9 kPa from Key ON engine off val-

ue.

Circuit Description

The Manifold Absolute Pressure sensor is a piezoelectric pressure sensor fitted to the manifold to measure the pressure internal to the manifold. It is combined in one sensor with the manifold air temperature sensor and referred to as the TMAP sensor. The MAP reading is used to determine the load and state of the en-gine. Because the sensor measures absolute pressure, with the Key ON, engine off, the reading should be atmospheric pressure, displayed as kPa (approximately 100 kPa at sea level). The sensor operates on 5 volts and sends a signal voltage on the output circuit to the ECU. The ECU uses the signal to determine correct fueling. Voltage varies from a low voltage when the MAP is low (below atmospheric) to high when the MAP is close to or at atmospheric pressure. If there is a failure in the 5 volt reference to the TMAP sen-sor, a code will be set. Depending on the 5 volt failure mode, the system may go to the Limp Home mode.

111

MAP DIAGNOSTIC AID

PSIa kPa PSIa kPa PSIa kPa 5 34.47 55 379.2116 105 723.9495 10 68.94757 60 413.6854 110 758.4233 15 103.4214 65 448.1592 115 792.8971 20 137.8951 70 482.633 120 827.3708 25 172.3689 75 517.1068 125 861.8446 30 206.8427 80 551.5806 130 896.3184 35 241.3165 85 586.0543 135 930.7922 40 275.7903 90 620.5281 140 965.266 45 310.2641 95 655.0019 145 999.7398 50 344.7379 100 689.4757 150 1034.214

kPa PSIa kPa PSIa kPa PSIa

5 0.725189 55 7.977074 105 15.22896 10 1.450377 60 8.702262 110 15.95415 15 2.175566 65 9.427451 115 16.67934 20 2.900754 70 10.15264 120 17.40452 25 3.625943 75 10.87783 125 18.12971 30 4.351131 80 11.60302 130 18.8549 35 5.07632 85 12.3282 135 19.58009 40 5.801508 90 13.05339 140 20.30528 45 6.526697 95 13.77858 145 21.03047

50 7.251885 100 14.50377 150 21.75566

MAP Output Voltage

0

20

40

60

80

100

120

0 1 2 3 4 5 6

Voltage

MA

P i

n k

Pa

112

DTC 106 MAP/Low/High/Short/Open Step Action Value(s) Yes No

1


Go to Step (2)


nostics System


lamp.

2

Key ON, engine off. Monitor the MAP reading. Does the monitor display MAP reading of 508 kPa on the digital display?

508 kPa Go to Step (3)

Intermittent problem. Go to Preliminary and Intermit-tent Checks.

3

Key OFF, disconnect C011 from the TMAP sensor

Key ON, measure the voltage across the C011 connector, pins 1 and 3.

Is voltage between 4.8 and 5.2 volts?

Between 4.8 and

5.2V Go to Step (4) Go to Step (5)

4

Replace known good MAP sensor and retest. Is everything OK? NOTE: Do not probe wires without proper ser-vice tool. Permanent harness damage may result.

Go to Step (7) Go to Step (5)

5

Key OFF, disconnect ECU-B Check resistance between C011 pin 1 and

ECU-B pin H4, C011 pin 3 and ECU-B pin H2, and C011 pin 4 and ECU-B pin H3.

Is resistance less than 5Ω?

<5Ω Go to Step (6)

Repair open in the wiring and Go to Step (7)

6

Refer to diagnostics for 5 volt reference vol-tage. See codes DTC 524260

Retest for 5 volts at Co11 pins 1 and 3 Is voltage now between 4.8 and 5.2 volts?

Between 4.8 and

5.2V Go to Step (7)


Step (7)

113


7





full operating temperature. Observe the MIL. Observe engine performance and driveabili-

ty. After operating the engine within the test pa-



System OK.


nostics System

Check/Malfunction Indicator

lamp.

114

DTC 110-ECT/Low/High/Short/Open

Conditions for Setting the DTC ECT sensor voltage less than 0.059. ECT sensor voltage greater than 4.888. ECT sensor voltage greater than 4.99. MIL - on during active fault and for 2 seconds after active fault.

Circuit Description The Coolant Temperature Sensor is a Negative Coefficient (as the temperature ris-es, the resistance drops) temperature sensitive resistor located in the Cylinder Head. The ECM uses the reading to determine temperature related operating condition re-quirements for the engine. Five volts is applied across the sensor and voltage drop is measured to determine the temperature.

Temp (deg F)

Ohms

242.4 101 231.9 121 211.6 175 201.4 209 181.9 302 163.1 434 144.9 625 127.4 901 102.4 1,556 78.9 2,689 49.9 5,576 23.5 11,562 -5.7 28,770

-21.2 49,715 -30.8 71,589 -40.0 99,301

115

DTC 110-ECT/Low/High/Short/Open


1

From Diagnostic tool, monitor ECT. Is the displayed temperature reading esti-

mated engine temperature Key ON, ECT should reflect engine tempera-ture?

Intermittent fault. See wir-

ing schematics and check

circuits from C034 to ECU-B for possible

short to ground.

Go to step2

2

Disconnect connector C034 From monitor, does temperature read 214° C? (Default)

Go to Step

(3) Go to Step

(4)

3

With C034 disconnected, measure the vol-tage across C034 pins A and B



Between 4.8 and 5.2 V

Replace the sensor. Go to Step (5)

Go to Step (4)

4

With C034 and ECU-B disconnected, meas-ure the resistance from C034 pin 1 to ECU-B pin F2, C034 pin 2 to ECU-B pin F4 and across C034 pins 1 and 2.

Is the resistance less than 5 ohms from C034 to ECU-B and greater than 30MΩ across C034?

<5Ω and >30MΩ


Step (5)

Repair fault in harness. Go to Step (5)

116

DTC 135 FRP Open/Short/High

Conditions for Setting the DTC FRP Sensor Check Condition-Key ON Fault Condition-FRP voltage greater than 4.94 volts Fault Condition-FRP voltage less than 0.25 volts MIL-ON Circuit Description The FRP (Fuel Rail Pressure) is a sensor that monitors the state of the LP fuel in the fuel rail. A pressure sensor located on the fuel rail monitors the fuel pressure. The output in conjunction with other sensors is used to determine the appropriate injector pulse to deliver the fuel. A lower output voltage indicates a low-er pressure, and higher voltage for higher pressure. This fault will set if the signal voltage is less than 0.25 or greater than 4.94 volts.

117

DTC 135 FRP Open/Short/High


1


Go to Step

(2)

Go to OBD System

Check Sec-tion

2

Key ON DST (Diagnostic Scan Tool) connected

with the Voltages and Service windows displayed.

Does the DST display FRP (Fuel Rail Pres-sure) voltage less than 0.20 volts?

Less than 0.20 volts?

Go to Step (4)

Go to Step (3)

3

Key OFF Disconnect the FRP sensor connector

C016 from the wiring harness. Jump the 5 volt reference B and FRP sig-

nal circuit C together. Key ON Does the DST display FRP voltage greater than 4.90 volts?

Greater than 4.90

volts

Go to Step (6)

Go to Step (5)

4

Inspect FRP connector and pins for corrosion, contamination or mechanical damage. Any problems found?

Repair the circuit as

necessary. See wire

harness re-pair section.

Go to Step (5)

5

Replace FRP Sensor. Is the replacement complete?

Go to Step (12)

6

Key ON Using a DVOM check for voltage between

FRP connector 5 volt reference ECU-B J2 and sensor ground pin A.

Does the DVOM display a voltage greater than 4.90 volts?

Greater than 4.90

volts

Repair the 5 volt refer-

ence circuit as neces-sary. See

wire harness repair sec-

tion

Go to Step (7)

7

Key OFF Disconnect ECU-B connector Check for continuity between FRP sensor

connector C and ECM signal pin J3. Do you have continuity between them?

Go to Step

(8)

Repair the open signal circuit. See wire harness repair sec-

tion.

118


8

Using a DVOM check for continuity be-tween FRP sensor connector signal A and sensor ground K2.



ground sig-nal circuit. See wire


Go to Step (9)

9

Using a DVOM check for continuity be-tween FRP sensor connector B and engine ground.



ground sig-nal circuit. See wire


Go to Step (10)

10

Inspect ECM connector and wire harness connector terminals for corrosion, conta-mination or mechanical damage.

Any problems found?

Repair har-ness and

connector as necessary. See wire


Go to Step (11)

11

Replace ECM. Is the replacement complete?

Go to Step (12)

12

Remove all test equipment except the DST.

Connect any disconnected components, fuses, etc.

Using the DST clear DTC information from the ECM.

Turn the ignition OFF and wait 30 seconds.

Start the engine and operate the vehicle to full operating temperature

Observe the MIL Observe engine performance and drivea-

bility


System OK Go to OBD

System Check

120

DTC 168 System Voltage Low/High

Conditions for Setting the DTC System Voltage Check Condition-Ignition ON Voltage high: battery voltage above 18.5 volts with the Key ON. Voltage low: battery voltage below 5.29 volts while the engine is running MIL-On

Circuit Description The system monitors battery voltage and will set a code if the voltage is out of range.

121

DTC 168 System Voltage Low/High


1

Perform charging system diagnostics. Was a fault found? NOTE: Do not probe wires without proper ser-vice tool. Permanent harness damage may result.

Repair as ne-cessary

Go to step 2

2

Key OFF, disconnect connector ECU-B. Using the proper tools, ground ECU-B pin

D4. Measure voltage from ECU-B M2 to M1. Is voltage within range?



Go to Step (3)

3

Measure voltage from ECU-B M2 to engine ground.

Is voltage within range?

Check all grounds and repair as ne-cessary. Go to Step (7)

Go to Step (4)

4

Remove Component Power Relay. Measure voltage from pins E8 and D8 to en-

gine ground. Is voltage within range?

System Vol-tage

Go to Step (6)

Go to Step (5)

6

Key OFF Disconnect ECU-B Measure the resistance from: ECU-B pin M2

to Component Power Relay pin C9 and ECU-B pin D4 to Component Power Relay pin A9


Replace the power latch relay. Go to

Step (7).

Repair open in harness as

necessary. Refer to Wire

Harness Repair. Go to

Step (7).

122

DTC 628 Cal Memory Failure

Conditions for Setting the DTC Engine Control Module Check Condition-Ignition ON Fault Condition-Internal microprocessor error MIL-On

Circuit Description

The ECM has several internal checks that must be satisfied each time an instruction is executed. Sev-eral different things can happen within the microprocessor that will cause this fault. This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM). This diagnostic al-so addresses if the ECM is not programmed or the program checksum does not match or has become corrupted. Always verify that the ECM was flashed with the proper calibration files before using the follow-ing diagnostic chat.

123

DTC 628 Cal Memory Failure


1


Go to step 2


nostics System


lamp.

2 Reprogram or replace the ECU as required. Is the repair completed?

Go to Step

(3)

3









System OK.


nostics System


lamp.

124

DTC 630 ECU Checksum Error


Circuit Description


125

DTC 630 ECU Checksum Error


1


Go to step 2


nostics System


lamp.


Go to Step

(3)

3









System OK.


nostics System


lamp.

126

DTC 651 Injector Short/Open

Conditions for Setting the DTC Short to B+ Open Circuit Short to Ground

Circuit Description The ECU injector circuit drives the LPG system.

127



1


Go to Step (2)


nostics System


lamp.

2

For DTC 651-3 short to B+, Go to Step (3) For DTC 651-5 Open Circuit, Go to Step (5) For DTC 651-6 Short to Ground, Go to Step

(11)

3

Disconnect injector connector Key OFF Disconnect ECU-B Is resistance between pin Measure voltage

from pin injector pin 2 to ground. Is voltage greater than zero?

>0V Go to Step

(4)

4

Key OFF, disconnect ECU-B Key ON, measure voltage from pin 2 to

ground. Is voltage greater than zero?

>0V

Repair short to power in

the harness. Go to step14

Replace ECU. Go to Step (14)

5

For affected cylinder, disconnect injector connector, Key ON

Measure voltage from pin 1 to ground. Is battery voltage present?

Battery Vol-tage

Go to Step (8)

Go to Step (6)

6

With C007 disconnected, Key ON Measure voltage at C007 pin 2 Is battery voltage present? Battery Vol-

tage

Repair open in harness between

C007 and in-jector

connector. Go to Step

(14)

Go to Step (7)

7

Key OFF, disconnect ECU-B. Measure resistance from C007 pin 1 to ECU-

B pin A1 Is resistance less than 5Ω?

<5 Ω

Refer to the wiring dia-

gram for your truck and re-pair power

supply prob-lem. Go to Step (14)

Repair open in the har-

ness. Go to Step (14)

8 Measure resistance of affected injector. Is resistance 2Ω ± .5Ω?

2Ω ± .5Ω Go to Step

(9)

Replace in-jector. Go to

Step (14)

128


9

Key OFF, C007 disconnected Measure the resistance of the control circuit.

See table above.

Is resistance less than 5Ω?

<5Ω Go to Step

(10)



10

Key OFF, ECU-B disconnected Measure the resistance of the control circuit

from C007 to ECU-B. Is the resistance less than 5 Ω?

<5Ω Replace

ECU. Go to Step (14)



11

With the affected cylinder disconnected, measure the resistance if the injector.

Is resistance 2Ω ± .5Ω?


(12)

Replace the injector. Go to

Step (14)

12

Measure resistance from the injector connec-tor pin 1 of the affected cylinder to ground.

Is the resistance greater than 30MΩ?

>30Ω Replace the ECU. Go to Step (14)

Go to Step (13)

13

Key OFF, ECU-B disconnected Measure the resistance from the control cir-

cuit to ground. Is the resistance greater than 30MΩ?

>30Ω

Repair the short to

ground in the harness. Go to Step (14)

Replace the ECU. Go to Step (14)

14









System OK.


nostics System


lamp.

130




131



1


Go to Step (2)


nostics System


lamp.

2


(11)

3

Disconnect injector connector Key OFF Disconnect ECU-B Measure voltage from injector pin 2 to


>0V Go to Step

(4)

4



>0V


the harness. Go to

Step(14)


5



Battery Vol-tage

Go to Step (8)

Go to Step (6)

6

With C008 disconnected, Key ON Measure voltage at C007 pin 2

Is battery voltage present? Battery Vol-

tage


C008 and in-jector


(14)

Go to Step (7)

7



<5 Ω








(9)


Step (14)

132


9


See table above. Is resistance less than 5Ω?

<5Ω Go to Step

(10)



10


from C007 to ECU-B pin 2. Is the resistance less than 5 Ω?

<5Ω Replace




11




(12)


Step(14)

12




Go to Step (13)

13



>30Ω

Repair the short to


Replace the ECU. Go to Step (14).

14









System OK.


nostics System


lamp.

134




135



1


Go to Step (2)


nostics System


lamp.

2


(11)

3



>0V Go to Step

(4)

4



>0V




5



Battery Vol-tage

Go to Step (8)

Go to Step (6)

6


tage


C009 and in-jector


(14)

Go to Step (7)

7



<5 Ω






8 Measure resistance of affected injector.



(9)


Step (14)

136


9



Go to Step

(10)



10



<5Ω Replace




11



<5Ω Go to Step

(12)


step14

12



2Ω ± .5Ω Replace the ECU. Go to Step (14)

Go to Step (13)

13



>30Ω

Repair the short to



14









>30Ω System OK.


nostics System


lamp.

138




139



1


Go to Step (2)


nostics System


lamp.

2


(11)

3



>0V Go to Step

(4)

4



>0V




5



Battery Vol-tage

Go to Step (8)

Go to Step (6)

6


tage


C010 and in-jector


(14)

Go to Step (7)

7



<5 Ω








(9)


Step (14)

140


9



<5Ω Go to Step

(10)



10



<5Ω Replace




11 With the affected cylinder disconnected,

measure the resistance if the injector. Is resistance 2Ω ± .5Ω?


(12)


step14

12




Go to Step (13)

13



>30Ω

Repair the short to



14









System OK.


nostics System


lamp.

142

DTC 1635 Code vs. Cal Version


Circuit Description


143

DTC 1635 Code vs. Cal Version


1


- Go to Step

(2)

Go to OBD System

Check Sec-tion

2

Ignition ON DST (Diagnostic Scan Tool) connected in

System Data Mode Clear system fault code Ignition OFF Ignition ON Does DTC 1635 reset with the Ignition ON?

Go to Step

(3)


section

3

Check ECM power and ground connections at ECU-B pins M2, M1, L1 and C001.

Did the power and ground circuits check OK? Go to Step

(4)



trical.

4

Re-flash the ECM with the correct calibration file

Repeat all in step (2). Does DTC 1635 still set?

Go to Step

(5) Go to Step

(6)

5 Replace ECM


Go to Step

(5) -

6



the ECM Turn the Ignition OFF and wait 30 seconds. Start the engine and run to full operating


rameters of DTC 1635 check for any stored codes


System OK Go to OBD

System Check

144

DTC 522545 MIL (Malfunction Indicator Lamp) Open

Circuit Description The Spectrum Fuel system is equipped with OBD (On-Board Diagnostics). The system has a dash mounted MIL (Malfunction Indicator Lamp). The MIL serves as notification of an emis-sions related problem. It will display DTCs that have been stored due to a possible system malfunction. The following DTC charts in this manual will instruct the technician to perform the OBD system check. This simply means to verify the operation of the MIL. The lamp should illuminate when the key is in the ON position, and the engine is not running. This fea-ture verifies that the lamp is in proper working order. If the lamp does not illuminate with the vehicle Key ON and engine OFF, repair it as soon as possible. Once the engine is in start or run mode, the lamp should go off. If the lamp stays on while the engine is in the start or run mode, a current diagnostic trouble code may be set or a problem may exist with the MIL elec-trical wiring. The electrical schematic above shows the MIL power source supplied to the lamp. The ECM completes the circuit to ground to turn the lamp ON.

146

DTC 522614 Throttle Failed to Enter Limp Home

Conditions for Setting the DTC Electronic Throttle Control Check Condition-Ignition ON Fault Condition-Throttle return spring test MIL-On during active fault

Circuit Description Dual throttle position sensors (TPS) are used with the electronic throttle control (ETC) to determine

throttle plate position. The TPS values are used by the ECM to determine if the throttle is opening and closing as commanded. The ECM runs several checks at ignition on to validate the working condition of the ETC. This fault will set if the ECM detects a problem with the ETC internal return spring.

147

DTC 522614 Throttle Failed to Enter Limp Home Step Action Value(s) Yes No


Go to Step (2)

Go to OBD System Check

Section

2


data stream mode. Clear DTC 522614 Ignition OFF Ignition ON Does DTC 522614 re-set?

Go to Step

(3)


section

3

Check the electronic throttle for a foreign object in the throttle bore or damaged throttle bore or fly assembly. Did you find damage or a foreign object in the bore?

Remove the foreign object or replace the

throttle if damage is

found. Go to Step (17)

Go to Step (4)

4

Ignition OFF Disconnect electronic throttle connector

C017 Disconnect ECM wire harness connector

ECU-B Using a DVOM check for continuity between

all electronic throttle connector pins and en-gine ground



ground TPS circuit as ne-

cessary. Refer to Wir-ing Repairs

Go to Step (5)

5

Using a DVOM check for continuity between electronic throttle connector pin 1 and ECU-B connector pin G3. Does the DVOM show continuity?

Go to Step

(6)

Repair the open circuit as


6

Using a DVOM check for continuity between electronic throttle connector pin 2 1 and ECU-B connector pin G2. Does the DVOM show continuity?

Go to Step

(7)


necessary. Refer to Wir-ing Repairs

7

Using a DVOM check for continuity between electronic throttle connector pin 3 and ECU-B connector pin M3. Does the DVOM show continuity?

Go to Step

(8)



148


8

Using a DVOM check for continuity between electronic throttle connector pin 4 and ECU-B connector pin D3. Does the DVOM show continuity?

Go to Step

(9)

Repair the shorted TPS

circuit to ground as ne-cessary. Refer to Wiring Re-

pairs.

9


Go to Step

(10)



pairs.

10


Go to Step

(11)



pairs.

11 Replace electronic throttle


Go to Step

(12) -

12




temperature. Observe the MIL Observe engine performance. After operating the engine within the test pa-



System OK Go to Step

(13)

13 Replace the ECM Is the replacement complete?

Go to Step

(14) -

149


14







System OK Go to OBD

System Check

150

DTC 522616 Throttle Actual vs. Commanded Error

Conditions for Setting the DTC Electronic Throttle Control Check Condition-Ignition ON Fault Condition-TPS 1 and 2 calculated values exceed 10% MIL-On during active fault

Circuit Description

Dual throttle position sensors (TPS) are used with the electronic throttle control (ETC) to determine throttle plate position. Although the actual voltage values between them are inverse, the calculated position values should remain very close. The TPS values are used by the ECM to determine if the throttle is open-ing and closing as commanded. This fault will set if the ECM detects more than a 10% difference in calculated values between TPS 1 and TPS 2.

151

DTC 522616 Throttle Actual vs. Commanded Error Step Action Value(s) Yes No


Go to Step (2)


Section

2



Go to Step

(3)


section

3





Go to Step (4)

4









Go to Step (5)

5


Go to Step

(6)



6


Go to Step

(7)



7


Go to Step

(8)



152


8


Go to Step

(9)



pairs.

9


Go to Step

(10)



pairs.

10


Go to Step

(11)



pairs.



Go to Step

(12) -

12








(13)


Go to Step

(14) -

153


14







System OK Go to OBD

System Check

154

DTC 522617 Throttle Failed to Fully Open/Close

Conditions for Setting the DTC Electronic Throttle Control Check Condition-Ignition ON Fault Condition-TPS 1 and 2 calculated values exceed 10% MIL-On during active fault

Circuit Description

Dual throttle position sensors (TPS) are used with the electronic throttle control (ETC) to determine throttle plate position. Although the actual voltage values between them are inverse, the calculated position values should remain very close. The TPS values are used by the ECM to determine if the throttle is open-ing and closing as commanded. This fault will set if the ECM detects more than a 10% difference in calculated values between TPS 1 and TPS 2.

155

DTC 522617 Throttle Failed to Fully Open/Close Step Action Value(s) Yes No


Go to Step (2)


Section

2


data stream mode. Clear DTC 522617 Start the engine Does DTC 522617 re-set?

Go to Step

(3)


section

3





Go to Step (4)

4









Go to Step (5)

5


Go to Step

(6)



6


Go to Step

(7)



7


Go to Step

(8)



8


Go to Step

(9)



pairs.

156


9


Go to Step

(10)



pairs.

10


Go to Step

(11)



pairs.



Go to Step

(12) -

12








(13)


Go to Step

(14) -

157


14







System OK Go to OBD

System Check

158

DTC 522630 Oxygen Sensor Failure to Switch Lean, Bank 1


The short term fuel correction has a range of ± 25%. If the correction reaches the upper or lower limit, it will then try an additional 2% change to watch for an O2 switch. If the sensor switches with the additional 2%, a short term fuel correction code will be set. If the sensor does not switch with the additional 2% change, the system will set a code for a sensor that fails to switch rich or lean.

Circuit Description

The system monitors the O2 sensor to ensure that the fuel control is functioning properly. The HEGO sen-sor is mounted in the exhaust system downstream of the engine. The HEGO sensor is used to measure the amount of oxygen present in the exhaust stream and communicates that to the ECM via an electrical signal. The amount of oxygen present in the exhaust stream indicates whether the fuel air ratio is rich or lean. If the HEGO sensor signal indicates that the exhaust stream is rich, the ECM will decrease or lean the fuel mixture by reducing the short term fuel correction value which reduces the injector on-time supplying less fuel. If the mixture is lean, the ECM will richen the mixture or increase the short term fuel correction value which will increase the pulse width to the injectors. Under normal steady operation the short term fuel correction value should move up and down approx. 5%. This 5% movement may range within a plus 25 to minus 25 percent window. The ECM continuously monitors the HEGO sensor output. If a rich or lean condition is present for an extended period of time and if the ECM cannot correct the condition, the ECM will set a diagnostic code and turn on the MIL light in the dash. NOTE: The HEGO sensor is sensitive to silicone and silicone-based products and can become contaminated. Avoid using silicone sealers or hoses treated with silicone lubricant in the air stream or fuel supply lines. Diagnostic Aids Low fuel pressure Partially blocked fuel injectors Manifold vacuum leaks Defective O2 sensor A misfire on one or more cylinders Exhaust leak ahead of the O2 sensor Faulty MAP sensor

159

DTC 522630 Oxygen Sensor Failure to Switch Lean, Bank 1 Step Action Value(s) Yes No

1


Go to Step

(2)

Go to On-Board



lamp.

2

With the engine at operating temperature, monitor the O2 sensor voltage and the short term fuel trim

Is the O2 sensor switching from rich to lean, and is the short term correction less than 25%?

No problems at this time. Intermittent problem. Go


Go to Step (3)

3

Check all problems listed in the diagnostic aids.

For the O2 sensor, also refer to DTC 522730 diagnostics.

For MAP diagnostics, refer to DTC 106 For ECT diagnostics, refer to DTC 110 Verify proper maintenance and condition of

the ignition system. Verify engine condition with a compression

test.

Were any faults found?

Repair as re-quired. Go to

step last

Go to Step (4)

4

Monitor connected with the engine running, monitor the engine RPM.

One at a time, disconnect each injector and observe the drop in engine speed.

Do one or more injectors not drop the engine speed when disconnected?

NOTE: the engine speed will only drop momen-tarily as the ECU corrects the engine speed.

Go to Step

(6) Go to Step

(5)

5

Check the fuel pressure. Is the pressure 88 kPa (12.8 PSI) above at-

mospheric pressure, engine off ±15 kPa (2.2 PSI) holding steady?

Go to Step

(6)

Replace the Regulator, Go

to Step (8).

6

Checking injectors One at time, connect a noid light across

each injector connector. With the engine running, does the noid light

flash at the connector of the failed injector connector?

Replace faul-ty injector Go

to Step (8)

Repair circuit to the injec-tor. Go to step last

160


7

Check pressure drop Check manifold vacuum supply to regulator

Is the pressure within specifications?

Replace the regulator. Go

to Step (8)

Verify the fil-ter is OK. Go to Step (8).

8









System OK.

Go to On-Board


Malfunction Indicator

lamp.

162

DTC 522631 Oxygen Sensor Failure to Switch Rich, Bank 1



Circuit Description

The system monitors the O2 sensor to ensure that the fuel control is functioning properly. The HEGO sensor is mounted in the exhaust system downstream of the engine. The HEGO sensor is used to meas-ure the amount of oxygen present in the exhaust stream and communicates that to the ECM via an electrical signal. The amount of oxygen present in the exhaust stream indicates whether the fuel air ratio is rich or lean. If the HEGO sensor signal indicates that the exhaust stream is rich, the ECM will decrease or lean the fuel mixture by reducing the short term fuel correction value which reduces the injector on-time supplying less fuel. If the mixture is lean, the ECM will richen the mixture or increase the short term fuel correction value which will increase the pulse width to the injectors. Under normal steady operation the short term fuel correction value should move up and down approx. 5%. This 5% movement may range within a plus 25 to minus 25 percent window. The ECM continuously monitors the HEGO sensor output. If a rich or lean condition is present for an extended period of time and if the ECM cannot correct the condi-tion, the ECM will set a diagnostic code and turn on the MIL light in the dash. NOTE: The HEGO sensor is sensitive to silicone and silicone-based products and can become contaminated. Avoid using silicone sea-lers or hoses treated with silicone lubricant in the air stream or fuel supply lines. Diagnostic Aids Low fuel pressure Partially blocked fuel injectors Manifold vacuum leaks Defective O2 sensor A misfire on one or more cylinders Exhaust leak ahead of the O2 sensor Faulty MAP sensor

163


1


Go to Step

(2)

Go to On-Board



lamp.

2





Go to Step (3)

3





test.



step last

Go to Step (4)

4





Go to Step

(6) Go to Step

(5)

5


mospheric pressure, engine off ±15 kPa (2.2 PSI) and holding steady?

Go to Step

(6)

Replace the vaporizer, Go to Step (8).

6





to Step (8)


164


7




to Step (8)


8









System OK.

Go to On-Board



lamp.

166

DTC 522635 Short Term Fuel Lean, Bank 1



Circuit Description


167


1


Go to Step

(2)

Go to On-Board



lamp.

2





Go to Step (3)

3





test.



step last

Go to Step (4)

4





Go to Step

(6) Go to Step

(5)

5



Go to Step

(6)

Replace the Regulator, Go

to Step (8).

6





to Step (8)


168


7




to Step (8)


8









System OK.

Go to On-Board



lamp.

170

DTC 522636 Short Term Fuel Lean, Bank 1



Circuit Description


171


1


Go to Step

(2)

Go to On-Board



lamp.

2





Go to Step (3)

3





test.



step last

Go to Step (4)

4





Go to Step

(6) Go to Step

(5)

5



Go to Step

(6)

Replace the Regulator. Go to Step

(8).

6





to Step (8)


172


7




to Step (8)


8









System OK.

Go to On-Board



lamp.

174

DTC 522690 Bus Failure

Conditions for Setting the DTC CAN Rx Check Condition-Engine running Fault Condition-CAN error packets lost, not received or corrupt MIL-ON

Circuit description

The CAN bus (controller area network) is used by the ECM to communicate with other digital devices used throughout the fuel system. Information is sent over the CAN bus in digital information “packets” that contain information for various control functions. This fault will set if the ECM detects continuous CAN communications hardware errors or CAN policy violations.

175

DTC 522690 Bus Failure


1


Go to Step

(2)

Go to On-Board



lamp.


Go to Step

(3)

3









System OK.

Go to On-Board



lamp.

176

DTC 522691 Redundant Check Failure


Circuit Description


177

DTC 522691 Redundant Check Failure


1


- Go to Step

(2)

Go to OBD System

Check Sec-tion

2



Go to Step

(3)


section

3

Check ECU-B power and ground connec-tions at M1, L1 and M2. Also check C001, C005, C003 and C015.

Did the power and ground circuits check OK?

Go to Step (4)



trical.

4


Repeat all in Step (2). Does DTC 522691 still set?

Go to Step

(5) Go to Step

(6)

5 Replace ECM


Go to Step

(5) -

6







System OK Go to OBD

System Check

178

DTC 522692 Redundant General Conversion Failure


Circuit Description


179



1


- Go to Step

(2)

Go to OBD System

Check Sec-tion

2



Go to Step

(3)


section

3



Go to Step (4)



trical.

4



Go to Step

(5) Go to Step

(6)

5 Replace ECM


Go to Step

(5) -

6







System OK Go to OBD

System Check

180

DTC 522694 Memory Checksum Error


Circuit Description


181

DTC 522694 Memory Checksum Error


1


- Go to Step

(2)

Go to OBD System

Check Sec-tion

2



Go to Step

(3)


section

3



Go to Step

(4)



trical.

4



Go to Step

(5) Go to Step

(6)

5 Replace ECM


Go to Step

(5) -

6







System OK Go to OBD

System Check

182



Circuit Description


183



1


- Go to Step

(2)

Go to OBD System

Check Sec-tion

2



Go to Step

(3)


section

3



Go to Step (4)



trical.

4



Go to Step

(5) Go to Step

(6)

5 Replace ECM


Go to Step

(5) -

6







System OK Go to OBD

System Check

184

DTC 522698 Redundant Clock Failure


Circuit Description


185

DTC 522698 Redundant Clock Failure


1


- Go to Step

(2)

Go to OBD System

Check Sec-tion

2



Go to Step

(3)


section

3



Go to Step (4)



trical.

4



Go to Step

(5) Go to Step

(6)

5 Replace ECM


Go to Step

(5) -

6







System OK Go to OBD

System Check

186

DTC 522699 Redundant Watchdog Failure


Circuit Description


187

DTC 522699 Redundant Watchdog Failure


1


- Go to Step

(2)

Go to OBD System

Check Sec-tion

2



Go to Step

(3)


section

3



Go to Step (4)



trical.

4



Go to Step

(5) Go to Step

(6)

5 Replace ECM


Go to Step

(5) -

6







System OK Go to OBD

System Check

188

DTC 522700 Redundant SDF Timeout


Circuit Description


189

DTC 522700 Redundant SDF Timeout


1


- Go to Step

(2)

Go to OBD System

Check Sec-tion

2



Go to Step

(3)


section

3

Check ECM power and ground connections at C001 pins E and F, C002, C012 and C016

Did the power and ground circuits check OK? Go to Step

(4)



trical.

4



Go to Step

(5) Go to Step

(6)

5 Replace ECM


Go to Step

(5) -

6







System OK Go to OBD

System Check

190



Circuit Description The electronic throttle body has two throttle position sensors TPS1 and TPS2. The voltage from these sensors is used to determine the percentage throttle opening. The TPS sensors have a nominal output range of 0.2 to 4.95 volts. From the throttle body itself TPS1 ranges from 0.2 to 4.95 volts as the throttle is opened, TPS2 ranges from 4.95 to 0.2 volts for this same closed to open travel. The ECM rectifies TPS2 signal so both signals on the diagnostic monitor read from 0.2 to 4.95 as the throttle is opened. The travel of the throttle plate from the fully closed to the fully open mechanical stops may not use this entire range of voltages. The ECM learns the actual range of voltages used and adjusts the THROTTLE POSITION read-ing to range from 0 to 100% over this used range of voltages. The system looks at both TPS signals and if the readings are outside of the upper and lower limits or do not agree with each within limits a code will be set. The following failure combinations and resulting outcomes are possible: a) TPS1 fails open or shorted, - MIL illuminated, ECM uses TPS2, normal engine operation b) TPS2 fails open or shorted, - MIL illuminated, ECM uses TPS1, normal engine operation c) TPS1 & 2 fail open or shorted, - MIL illuminated, ECM stops controlling throttle, throttle goes to limp

home position and is non-responsive, engine will high idle or allow truck to move slowly. d) TPS1 & 2 do not match, - MIL illuminated, ECM will use the higher of the two TPS readings resulting in


191





TPS1 reading

on Moni-tor

TPS2 reading on Monitor

Throttle Position on

Monitor

Fully closed

0.32 4.70 0.32 0.30 0

¼ Open 1.32 3.70 1.32 1.30 25 ¾ Open 3.32 1.70 3.32 3.30 75

Fully Open 4.32 0.70 4.32 4.30 100 CONDITIONS FOR SETTING THE DTC A short circuit code will set if the TPS1 (as shown on the diagnostic monitor) is greater than 99.02% of

the 5 Volt Power Supply 1 (approx. 4.95 volts) A short circuit code will set if the TPS2 (as shown on the diagnostic monitor) is greater than 99.8% of



Volt Power Supply 1 (approx. 0.2 volts) Also see DTC 51.

192



1


NOTE: If the 5 volt reference Supply 1 is shorted to ground, various codes may set, including Throttle, Pedal 1, Oil Pressure, Cam and 5 Volt Power Supply Codes .If multiple codes are set, refer to diagnostics for codes 524261 to verify 5 volt reference.

Go to Step

(2)


nostics System


lamp.

2



TPS 2 voltage above 4.99 Is the higher voltage minus the lower voltage di-vided by 5 then multiplied by 100 greater than 6?

NOTE: this is the formula the ECU uses to de-termine if the TPS readings are within the specifications

Go to Step

(3)



3




Go to Step

(5) Go to Step (4)

4



ECU B pin G4





Step (9)



Go to Step (9)

193


5




Go to Step

(6)



6





the 5 volt supply before proceeding. Replace the ECU. Go to

Step (7)



(7).

7








System OK.

Go to On-BoardDiagnostics

System Check/Malfuncti

on Indicator lamp.

194



Circuit Description The electronic throttle body has two throttle position sensors TPS1 and TPS2. The voltage from these sensors is used to determine the percentage throttle opening. The TPS sensors have a nominal output range of 0.2 to 4.95 volts. From the throttle body itself TPS1 ranges from 0.2 to 4.95 volts as the throttle is opened, TPS2 ranges from 4.95 to 0.2 volts for this same closed to open travel. The ECM rectifies TPS2 signal so both signals on the diagnostic monitor read from 0.2 to 4.95 as the throttle is opened. The travel of the throttle plate from the fully closed to the fully open mechanical stops may not use this entire range of voltages. The ECM learns the actual range of voltages used and adjusts the THROTTLE POSITION read-ing to range from 0 to 100% over this used range of voltages. The system looks at both TPS signals and if the readings are outside of the upper and lower limits or do not agree with each within limits a code will be set. The following failure combinations and resulting outcomes are possible: a) TPS1 fails open or shorted, - MIL illuminated, ECM uses TPS2, normal engine operation b) TPS2 fails open or shorted, - MIL illuminated, ECM uses TPS1, normal engine operation c) TPS1 & 2 fail open or shorted, - MIL illuminated, ECM stops controlling throttle, throttle goes to limp

home position and is non-responsive, engine will high idle or allow truck to move slowly. d) TPS1 & 2 do not match, - MIL illuminated, ECM will use the higher of the two TPS readings resulting in


195





TPS1 reading

on Moni-tor

TPS2 reading on Monitor

Throttle Position on

Monitor

Fully closed

0.32 4.70 0.32 0.30 0

¼ Open 1.32 3.70 1.32 1.30 25 ¾ Open 3.32 1.70 3.32 3.30 75

Fully Open 4.32 0.70 4.32 4.30 100 CONDITIONS FOR SETTING THE DTC A short circuit code will set if the TPS1 (as shown on the diagnostic monitor) is greater than 99.02%

of the 5 Volt Power Supply 1 (approx. 4.95 volts) A short circuit code will set if the TPS2 (as shown on the diagnostic monitor) is greater than 99.8% of



Volt Power Supply 1 (approx. 0.2 volts) Also see DTC 51.

196



1


NOTE: If the 5 volt reference Supply 1 is shorted to ground, various codes may set, including Throttle, Pedal 1, Oil Pressure, Cam and 5 Volt Power Supply Codes .If multiple codes are set, refer to diagnostics for codes 524261 to verify 5 volt reference.

Go to Step

(2)


nostics System


lamp.

2



TPS 2 voltage above 4.99 Is the higher voltage minus the lower voltage

divided by 5 then multiplied by 100 greater than 6.


Go to Step

(3)



3




Go to Step

(5) Go to Step (4)

4



ECU B pin G4 Is the resistance less than 5Ω?




Step (9)



Go to Step (9)

197


5




Go to Step

(6)



6





the 5 volt supply before proceeding. Replace the ECU. Go to

Step (7)



(7).

7








System OK.


nostics System


lamp.

198






Then 12 to 25 %





199



1


Go to Step (2).

Go to On-Board



lamp.

2








Step (3).

3

Check pedal position sensor Disconnect VIC 1 Key ON, measure voltage from VIC 1 pins S

and R. Key ON, measure voltage from VIC 1 pins M


Between 4.8 and 5.2 volts?

Go to Step (5)

Go to Step (4)

4



Between 4.8 and 5.2 volts?


cessary.






200


5




Sweep, watch for glitch Repeat on other side NOTE: Pin J will show ½ the voltage of pin K.

This is normal operation Does the voltage sweep with no glitches from greater than 0.09 volts to less than 4.97 volts on pin A and from greater than 0.09 to less than 2.49 volts on pin B?




Go to step 6




sor. Go to step 8.

6




<5Ω? Go to step 7

Repair the open in the harness. Go

to step 8

7



Repair or replace the harness. Go to Step (8)


Step (8).

8









System OK.

Go to On-Board



lamp.

202






Then 12 to 25 %





203



1


Go to Step (2)

Go to On-Board



lamp.

2








Step (3).

3

Check pedal position sensor Disconnect VIC 1 Key ON, measure voltage from VIC pins S

and R. Key ON, measure voltage from VIC pins M


Between 4.8 and 5.2 volts

Go to Step (5)

Go to Step (4)

4





cessary.






204


5




Sweep, watch for glitch Repeat on other side NOTE: Pin J will show ½ the voltage of pin K. This is normal operation Does the voltage sweep with no glitches from greater than 0.09 volts to less than 4.97 volts on pin A and from greater than 0.09 to less than 2.49 volts on pin B?



proper posi-tions in the connector. Go to Step

(6)




sor. Go to Step (8).

6




Go to Step

(7)

Repair the open in the harness. Go to Step (8)

7




harness. Go to Step (8)


Step (8).

205


8









System OK.

Go to On-Board



lamp.

206

DTC 522735 Oxygen Sensor Short/Open

Conditions for Setting the DTC Heated Oxygen Sensor Check Condition-Ignition ON Fault Condition-Less than 30mv MIL-On

Circuit Description The EGO sensor (Exhaust Gas Oxygen) sensor is used to determine if the fuel flow to the engine is

correct by measuring the oxygen content in the exhaust gas. The EGO sensor uses an internal heating element to keep the sensor active. This fault will set if the ECM detects a short low or open in the HEGO heater element or control circuit. NOTE: The HEGO sensor is sensitive to silicone and silicone-based products and can become contaminated. Avoid using silicone sealers or hoses treated with silicone lubri-cant in the air stream or fuel supply lines.

207

DTC 522735 Oxygen Sensor Short/Open Step Action Value(s) Yes No

1


- Go to Step

(2)

Go to OBD System

Check Sec-tion

2

Ignition OFF Disconnect HEGO connector C018 Ignition ON Using a DVOM check for voltage between

EGO connector pins C and D Does the DVOM show voltage?

System Bat-tery Voltage

Go to Step (8)

Go To Step (3)

3

Ignition ON Using a DVOM check for voltage between

HEGO connector pin C and engine ground

Do you have voltage?


Repair open HEGO heater supply circuit from power relay. See

wire harness repair.

Go to Step (4)

4

Using a DVOM check for voltage between HEGO connector pin D and battery positive

Ignition ON Do you have voltage?


Repair open HEGO

ground cir-cuit. See

wire harness repair.

Go to Step (5)

5

Ignition OFF Disconnect ECU-C Connector Using a DVOM check for continuity between

ECU-C connector pin L2 and HEGO connec-tor pin D


Go to Step

(6)

Repair the open HEGO

heater ground. See wire harness

repair.

6

Ignition ON Using a DVOM check for voltage between

HEGO connector pin D and battery positive Does the DVOM show voltage?

Repair the HEGO heater ground short-ed to voltage. See wire har-ness Repair.

Go to Step (7)

7 Replace ECM


Go to Step

(10) -

208


8

Using a DVOM measure the resistance of the HEGO heater (sensor side) between pins C and D. Does the DVOM show a resistance value greater than 25 Ohms?

Greater than 25 Ohms

Go to Step (9)

Go to Step (5)

9 Replace the HEGO sensor Is the replacement complete?

Go to Step

(10) -

10



the ECM. Turn the Ignition OFF and wait 30 seconds. Start the engine and run to full operating

temperature Observe the MIL Observe engine performance. After operating the engine within the test pa-



System OK Go to OBD

System Check

210

DTC 522739 Oxygen Sensor Short/Open

Conditions for Setting the DTC The maximum current, current to ground, and drain voltage are monitored internally to the ECU. If the cur-rent at the driver chip goes above 3 amps, current to ground goes above 100 micro Amps, or voltage drops below 3 volts, a diagnostic code will be set.

Circuit Description

The system monitors the O2 sensor to ensure that the fuel control is functioning properly. The HEGO sen-sor is mounted in the exhaust system downstream of the engine. It is used to measure the amount of oxygen present in the exhaust stream and communicates that to the ECM via an electrical signal. The amount of oxygen present in the exhaust stream indicates whether the fuel air ratio is rich or lean. If the HEGO sensor signal indicates that the exhaust stream is rich, the ECM will decrease or lean the fuel mix-ture by reducing the short term fuel correction value which reduces the injector on-time supplying less fuel. If the mixture is lean, the ECM will richen the mixture or increase the short term fuel correction value which will increase the pulse width to the injectors. Under normal steady operation the short term fuel correction value should move up and down approx. 5%. This 5% movement may range within a plus 25 to minus 25 percent window. The ECM continuously monitors the HEGO sensor output. If a rich or lean condition is present for an extended period of time and if the ECM cannot correct the condition, the ECM will set a di-agnostic code and turn on the MIL light in the dash. The O2 sensor uses a heater circuit to bring it up to operating temperature as quickly as possible, as well as maintaining the temperature during idle. The hea-ter is controlled by the ECU, which will cycle the heater to prevent overheating of the sensor

211

DTC 522739 Oxygen Sensor Short/Open Step Action Value(s) Yes No

1


Go to Step

(2)

Go to On-Board



lamp.

2

Key OFF, disconnect C018 Key ON, measure voltage from C018 pin D

to ground. Is battery voltage present? NOTE: Voltage is supplied from the Component Power Relay circuit and will only be present for 1 to 2 seconds when the key is first turned on.

Go to Step

(3)

Repair open in Component Power Relay circuit. Go to

Step (8)

3

Measure resistance across the O2 sensor heater circuit, pins C and D.

Is the resistance 9.6Ω, ± 1.5Ω @ 21˚C?

9.6Ω, ± 1.5Ω @ 21˚C?

Go to Step (4)

Replace the O2 Sensor. Go to Step

(8)

4

Measure the resistance from the O2 sensor heater circuit pins C and D to ground

Is the resistance greater than 30MΩ? NOTE: Do not probe wires without proper ser-vice tool. Permanent harness damage may result.

>30MΩ Go to Step

(5)

Replace the O2 Sensor. Go to Step

(8)

5

Key OFF, disconnect ECU-C Measure resistance from C018 pin C to

ECU-C pin L2 Is the resistance less than 5Ω?

<5MΩ Go to Step

(6)

Repair the open in the

circuit. Go to Step (8)

6

Measure the resistance from C018 pin C to ground.


>30MΩ Go to Step

(7)

Repair the short to


7

Key ON, engine running, monitor the system for faults

Flex the connectors at the ECU while watch-ing for faults

Was a fault indicated by wiggling the wires?


ECU harness. Go to Step

(8)


Step (8)

212


8









System OK.

Go to On-Board



lamp.

214

DTC 522752 Start Failure Due to Cam Signal Error

Conditions for setting the DTC This fault will set if the ECU does not detect a cam pulse within 16 engine revolutions whenever the engine is cranking or running.

Circuit Description The camshaft position sensor (CMP) is a Hall Effect sensor used to synchronize the fuel and ignition sys-tems. The sensor produces a short 5 volt square wave pulse every two engine revolutions. The signal wire from the CAM sensor is held up at 5 volts by a pull-up resistor in the ECU. The CAM sensor pulls this 5 volt level to ground until a small hole in the end of the camshaft passes the sensor at which time the sig-nal goes high to 5 volts for a brief period.

215

DTC 522752 Start Failure Due to Cam Signal Error


1 Did you perform the On-board diagnostics (OBD) system check?

Go to step 2 Perform OBD System check

2

Check connections at C004, ECU-B pin M1, M2, L1, and ECU-C pins A4 and F1.



Go to Step (3)

3

Key OFF, disconnect C004 Connector. Key ON, measure voltage across C004 pins

A and C.



Go to Step (4)

Go to Step (5)

4

Reconnect C004. Using suitable probe, back probe C004 pins

B and C. Connect a Multi-meter capable of measuring

Duty Cycle, + to pin B, - to pin C. Crank the engine. Does the duty cycle read 90% (or 10%)? Duty cycle can show either 90% or 10% ±5% depend-ing on the meter.

Go to Step

(5)

Replace Cam Sensor, Go to

Step (9)

5

Wiring check Key OFF, disconnect ECU-C and C004 Measure resistance from : C004 pin A to ECU-C pin A4 C004 pin B to ECU-C pin F1 C004 pin C to ECU-B pin M2 Is resistance less than 5Ω?

<5Ω Go to Step

(6)


cessary. Refer to Wire

Harness Repair. Go to

Step (9)

6

Key OFF, disconnect ECU-C and C004 Measure resistance from : C004 pin A to ground. C004 pin B to ground C004 pin C to ground Is resistance greater than 30MΩ?

>30MΩ Go to Step

(7)

Repair short to ground as necessary.

Refer to Wire Harness

Repair. Go to Step (9)

7

Key OFF, disconnect ECU-C and C004 Measure resistance from : C004 pin A to C004 pin B C004 pin A to C004 pin C C004 pin B to C004 pin C

Is resistance greater than 30MΩ?

>30MΩ Go to Step

(8)

Repair short in harness.

Refer to Wire Harness re-pair. Go to

Step (9)

8 Replace ECU computer. Is replacement completed?

Go to Step

(9)

216


9









System OK


nostics System


lamp.

218

DTC 523821 Oil Lamp Circuit Open

Conditions for Setting the DTC Engine Low Oil Pressure Signal Check Condition-Engine running for greater than 10 seconds with engine speed greater than 500 rpm. Fault Condition-No oil pressure signal for more than 5 seconds Engine shut down

Circuit Description

The Oil Pressure Switch is used to communicate a low oil pressure condition to the ECM. Engine damage can occur if the engine is operated with low oil pressure. This fault will set if the oil pressure switch remains closed with the engine running. The switch is set to open above 6 PSI. Circuit Description Never assume the fault is due to an electrical malfunction. Low oil pressure can damage the engine. Verify oil pressure before proceeding with this diagnostic.

219

DTC 523821 Oil Lamp Circuit Open Step Action Value(s) Yes No

1


- Go to Step

(2)

Go to OBD System.

Check Sec-tion

2

Verify that the engine has oil and oil pressure using a mechanical oil pressure gauge before proceeding with this chart. Oil pressure must remain above 6 psi. Does the engine have oil pressure above 6 psi?

Go to Step

(3) Repair faulty

Oiling System

3

Ignition ON, Engine Running DST connected in stem Data Mode

Clear DTC 523821 Warm the engine by idling until the ECT

temperature is above 160 degrees F. and has been running for at least one minute

Increase engine speed above 500 RPM Does DTC 523821 reset?

Go to Step

(4)


section

4

Clear DTC 523821 Key OFF Disconnect oil pressure switch connector

C012 and isolate the connector from engine ground.

Start and run the engine Does DTC 523821 reset?

Go to Step

(6) Go to Step

(5)

5 Replace oil pressure switch


Go to Step

(9) -

6

Ignition OFF Disconnect ECM harness connector ECU-C Using a DVOM check for continuity between

the oil pressure switch connector pin and en-gine ground


Repair the shorted to ground oil

pressure cir-cuit as


Go to Step (7)

7

Inspect ECU-B connector pin C1 for damage corrosion or contamination Did you find a problem?



trical.

Go to Step (8)

220


8 Replace ECM Is the replacement complete?

Go to Step

(9) -

9





rameters of DTC 523821check for any stored codes.


System OK Go to OBD

System Check

222

DTC 524260 5 Volt Power Supply 1 Out of Spec

Conditions for Setting the DTC The voltage output of the two power supplies are compared against two range limits. The first “Out of Spec” limits are 4.8 to 5.2 volts the second “Malfunction” limits are 4.5 to 5.5 volts. If the 5 volts supplies are outside the “Out of Spec” limits but not outside the broader “Malfunction” limits the sensors and com-ponents will continue to operate but at a reduced accuracy. If the 5 volt supplies are outside the malfunction range sensors and components may fail to operate. The voltage being outside the malfunction limits may be an indication of a short to ground or short to battery voltage somewhere in the system. Voltage supply at the 5 volt reference is less than 4.8 volts or greater than 5.2 volts. NOTE: If the 5 volt supply is shorted to ground through wiring or a sensor, this code may set.

Circuit Description The ECU has two externally available 5 volt regulated power supplies. These power supplies are used as a power source and or a reference voltage for the various sensors and components used in the fuel sys-tem. If there is an out of spec fault in either 5 volt supply, the system will go to the Limp Home mode. 5 Volt Supply 1 Table Supply 1 ECU-A pin G2 Pedal 1 5 volt supply VIC 1 pin M ECU-B pin G1 Not Used ECU-B pin G2 Throttle position sensor supply pin 2 ECU-C pin B3 Not Used 5 Volt Supply 2 Table Supply 2 ECU-A pin F2 Pedal 2 5 volt supply VIC 1 pin S ECU-B pin J2 FRP Pin B and Crank Sensor Pin 1 ECU-B pin H2 MAP Sensor supply pin 3

223



1


Go to Step (2)


nostics System


lamp.

2

Disconnect all sensors for the 5 volt supply showing the fault.

Refer to the wiring diagram and measure the voltage from the 5 volt supply to the ground of each sensor or component

Are all supplies between 4.8 and 5.2 volts?


Go to Step (3)

Go to Step (5)

3

One at a time, reconnect a sensor while monitoring the voltage at another sensor.

Does the voltage go out of range when recon-necting a sensor?

Go to Step

(4)



4

Examine the connector of the sensor that causes the voltage to go out of range.

Is there any damage to the connector?

Repair as ne-cessary. Go to Step (8).

Replace the sensor that causes the fault in the

voltage. Go to step last

5

Refer to the 5 volt supply table and check each supply circuit for a short to power or ground.

Are there any harness faults?


Step (8).

Go to Step (6)

6

Reconnect all connectors. Clear all codes. With the Key ON, engine off, monitor the sys-

tem for any faults. Does the fault return? Are any faults detected?


Step (8)

Go to Step (7)

7

Flex the connectors at the ECU while watch-ing for faults.

Does the fault return?


harness. Go to Step (8).



224


8









System OK.


nostics System


lamp.

226


Conditions for Setting the DTC The voltage output of the two power supplies are compared against two range limits. The first “Out of Spec” limits are 4.8 to 5.2 volts the second “Malfunction” limits are 4.5 to 5.5 volts. If the 5 volts supplies are outside the “Out of Spec” limits but not outside the broader “Malfunction” limits the sensors and com-ponents will continue to operate but at a reduced accuracy. If the 5 volt supplies are outside the malfunction range sensors and components may fail to operate. The voltage being outside the malfunction limits may be an indication of a short to ground or short to battery voltage somewhere in the system. Voltage supply at the 5 volt reference is less than 4.8 volts or greater than 5.2 volts. NOTE: If the 5 volt supply is shorted to ground through wiring or a sensor, this code may set.

Circuit Description The ECU has two externally available 5 volt regulated power supplies. These power supplies are used as a power source and or a reference voltage for the various sensors and components used in the fuel sys-tem. If there is an out of spec fault in either 5 volt supply, the system will go to the Limp Home mode. 5 Volt Supply 1 Table Supply 1 ECU-A pin G2 Pedal 1 5 volt supply VIC 1 pin M ECU-B pin G1 Not Used ECU-B pin G2 Throttle position sensor supply pin 2 ECU-C pin B3 Not Used 5 Volt Supply 2 Table Supply 2 ECU-A pin F2 Pedal 2 5 volt supply VIC 1 pin S ECU-B pin J2 FRP Pin B and Crank Sensor Pin 1 ECU-B pin H2 MAP Sensor supply pin 3

227



1


Go to Step

(2)


nostics System


lamp.

2

Disconnect all sensors for the 5 volt supply showing the fault.

Refer to the wiring diagram and measure the voltage from the 5 volt supply to the ground of each sensor or component.

Are all supplies between 4.8 and 5.2 volts?


Go to Step (3)

Go to Step (5)

3

One at a time, reconnect a sensor while monitoring the voltage at another sensor.

Does the voltage go out of range when recon-necting a sensor?

Go to Step

(4)



4

Examine the connector of the sensor that causes the voltage to go out of range.

Is there any damage to the connector?

Repair as ne-cessary. Go to Step (8).

Replace the sensor that causes the fault in the

voltage. Go to step last

5

Refer to the 5 volt supply table and check each supply circuit for a short to power or ground.

Are there any harness faults?


Step (8).

Go to Step (6)

6

Reconnect all connectors. Clear all codes. With the Key ON, engine off, monitor the sys-

tem for any faults. Are any faults detected?


Step (8)

Go to Step (7)

7

Flex the connectors at the ECU while watch-ing for faults.

Does the fault return?


harness. Go to Step (8).



228


8









System OK.


nostics System


lamp.

230

DTC 524266 ETC Wire Shorted/Fail

Conditions for Setting the DTC Throttle Position Sensor Check Condition-Ignition ON Fault Condition-Actual and desired throttle position greater than 10% Battery voltage greater than 9 volts MIL-On during active fault

Circuit Description

Dual throttle position sensors (TPS) are used with the electronic throttle control (ETC) to determine throttle plate position. The TPS values are used by the ECM to determine if the throttle is opening and closing as commanded. This fault will set if the ECM detects a problem with the ETC TPS, malfunctioning throttle control motor or sticking throttle valve assembly.

231




Go to Step (2)


Section

2



Go to Step

(3)


section

3





Go to Step (4)

4









Go to Step (5)

5


Go to Step

(6)



6


Go to Step

(7)



7


Go to Step

(8)



232


8


Go to Step

(9)



pairs.

9


Go to Step

(10)



pairs.

10


Go to Step

(11)



pairs.



Go to Step

(12) -

12








(13)


Go to Step

(14) -

233


14







System OK Go to OBD

System Check

234


Conditions for Setting the DTC Throttle Position Sensor Check Condition-Ignition ON Fault Condition-Actual and desired throttle position greater than 10% Battery voltage greater than 9 volts MIL-On during active fault

Circuit Description

Dual throttle position sensors (TPS) are used with the electronic throttle control (ETC) to determine throttle plate position. The TPS values are used by the ECM to determine if the throttle is opening and closing as commanded. This fault will set if the ECM detects a problem with the ETC TPS, malfunctioning throttle control motor or sticking throttle valve assembly.

235




Go to Step (2)


Section

2



Go to Step

(3)


section

3





Go to Step (4)

4









Go to Step (5)

5


Go to Step

(6)



6


Go to Step

(7)



7


Go to Step

(8)



8


Go to Step

(9)



pairs.

236


9


Go to Step

(10)



pairs.

10


Go to Step

(11)



pairs.



Go to Step

(12) -

12








(13)


Go to Step

(14) -

14







System OK Go to OBD

System Check

237

Servicing the Fuel System

238

I. ENGINE CONTROL MODULE This procedure relates to removal and installation of the ECM--see Diagnostic Scan Tool for access-ing ECM software.

REMOVAL PROCEDURE

ECM 1. Disconnect the negative battery cable. 2. Disconnect the electrical connectors from the

ECM. Rotate the locking tabs on each connec-tor to unlock the electrical connectors. Disconnect the connector closest to the nega-tive battery terminal first. Disconnect the center connector second. Disconnect the con-nector closest to the positive battery terminal last.

3. Remove the screws securing the ECM,

INSTALLATION PROCEDURE 1. Place the ECM in position and secure with

screws. Tighten the nuts to 9 to 11 N•m (79.66 to 97.36 in. lbs).

2. Connect the electrical connectors to the ECM. Connect the electrical connector closest to the positive battery terminal first. Connect the cen-ter connector second. Connect the connector closest to the negative battery terminal last. Rotate the locking tabs to lock the electrical connectors in position.

3. Connect the negative battery cable. 4. Turn the ignition key to the ON position 5. Start the vehicle and check for proper opera-

tion of the electronic throttle body and the ECM by exercising the accelerator pedal with the vehicle in neutral.

II. FUSE BOX MOUNTING BRACKET

REMOVAL PROCEDURE 1. Disconnect the negative battery cable 2. Remove the four Screws, Washers and

Spacers securing the ECM to the Bracket. 3. Remove the two Bolts securing the Fuse Box

bracket to the Coil Bracket.

INSTALLATION PROCEDURE 1. Secure the Coil Bracket and Fuse Box bracket

by placing with two Bolts to the engine. Tor-que 29.5-36.8 ft.lbs. (40-50 Nm).

2. Attach the Fuse Box with four Screws (if re-moved). Torque to 2-3 ft. lbs. (2.7-4 Nm).

III. ENGINE WIRE HARNESS REPLACEMENT 1. Disconnect negative battery cable. 2. Lay out the new Wire Harness, noting the lo-

cation, type of connectors, and identifying markings. Take special note of identical or similar connectors (such as the coils or HEGO Sensors) to avoid crossing connections during installation. NOTE the routing of the existing wire harness in and around the engine and the vehicle. Refer to the Electrical Schematic.

239

Ensure that all connections are made to the correct locations on the engine and its components. Crossing connections may cause poor engine performance, a MIL warning and/or permanent damage to the ECM.

3. Remove all Wire Harness connectors on the

vehicle. 4. Remove all clips and brackets holding the

Wire Harness and remove harness from ve-hicle.

5. Lay the new wire harness over the engine and route each end to its connection. Verify that all connectors match prior to installation.

6. Connect all connectors and Ring Terminals. 7. Install all clips and brackets to hold down the

harness. 8. Reconnect negative battery cable. 9. Start the vehicle. 10. Check for MIL illumination. If a DTC code is

found, refer to the Electrical Section for further diagnosis.

IV. OIL PRESSURE SENDER

The Oil Pressure Sender, shown installed on the side of the engine below the ECM and above the starter. REMOVAL PROCEDURE 1. Disconnect the negative battery cable. 2. Locate the Oil Pressure Sender on the side of

the engine.

3. Remove electrical connection from Oil Pres-sure Sender.

4. Using a wrench, hold the brass adapter (to prevent from turning) and turn the Switch counter-clockwise and remove. Do not re-move the brass adapter from the engine block (unless it is to be replaced).

INSTALLATION PROCEDURE

1. Apply Loctite 567 (or equivalent high-temp

thread locker/sealer) to the threads on the Oil Pressure Sender. If the Brass Adapter was removed or is to be added to a new Sender, add thread locker/sealer and thread on to the engine block. Torque to 2-3 turns past tight.

2. Install Oil Pressure Sender. Torque to 2-3 turns past tight, ensuring the electric con-nector (screw) is accessible.

3. Attach electrical connector. 4. Reconnect negative battery cable. 5. Start the engine and let run until it reaches

normal operating temperature. Check for oil leaks around sensor. If leaks are found, repair as necessary.

6. If a DTC code is found, refer to the Electrical Section for further diagnosis.

V. DISTRIBUTOR

The Distributor

REMOVAL PROCEDURE 1. Disconnect negative battery cable. 2. Mark each Spark Plug Wire with its corres-

ponding cylinder or position on the Distributor

240

Cap. 3. Remove Spark Plug Wires from the Distributor

Cap by pulling and twisting each Spark Plug Wire boot ½ turn.

4. Remove Ignition Coil wire. 5. Remove the electrical connector from the

base of the Distributor. 6. Remove the two Screws that hold the Distribu-

tor Cap to the housing and remove Cap. 7. Using a grease pencil or similar marking tool,

mark the location of the Rotor on the distribu-tor housing and engine.

8. Remove the Distributor hold down bolt.

IMPORTANT Do not engage the starter, or change the positions of the cam or crankshaft, timing gears or any oth-er internal engine components while the distributor is removed. Any change in the position of these components will alter the timing.


1. Align the Rotor with the mark made on the Distributor housing (the location of the rotor when it was removed) and place into the en-gine ensuring the rotor, distributor housing and the mark on the engine are all in align-ment when the Distributor is fully seated.

2. Install the Distributor mounting clam Bolt and tighten to 18 ft. lbs (25 Nm). Verify that the rotor and Distributor housing remain in line with the mark.

3. Install Distributor Cap. IMPORTANT Do not reuse old Distributor Cap Screws. Use new Screws only. 4. Connect the electrical connection to the base

of the Distributor. 5. Connect Spark Plug wires to the Distributor

Cap, ensuring the wires are connected to the correct cylinder. NOTE that the firing order is 1-3-4-2. Refer to the IGNITION SYSTEM SPECIFICATIONS in the Appendix for addi-tional information.

6. Connect Ignition Coil wire to Distributor Cap. 7. Reconnect negative battery cable. 8. Start engine. Run engine through all throttle

ranges and under load to ensure normal oper-ation.

9. Using the DST, clear DTC information from the ECM.


VI. TEMPERATURE MANIFOLD PRESSURE SENSOR (TMAP)

REMOVAL PROCEDURE 1. Disconnect the negative battery cable. 2. Locate the TMAP Sensor on the Intake Mani-

fold plenum. 3. Disconnect electrical connector. 4. Remove the retaining screw. 5. Remove TMAP Sensor by pulling straight up

with a slight rocking motion.

TMAP Sensor


1. Install the TMAP and secure with Retaining Screw. Torque to 7-9 ft.lbs. (9.5-12.2 Nm).

2. Reconnect electrical connector. 3. Reconnect the negative battery cable. 4. Start engine and run until it reaches normal

operating temperature. 5. Check for MIL illumination. If a DTC code is

found, refer to the Electrical Section for further diagnosis.

241

VII. FUEL TEMPERATURE/PRESSURE SENSOR

REMOVAL PROCEDURE 1. Relieve the LPG fuel system pressure. Refer

to XVIII. LPG FUEL SYSTEM PRESSURE RELIEF.

2. Disconnect the negative battery cable. 3. Locate the Fuel Temperature Sensor on the

fuel rail. 4. Remove the electrical connector from the

Sensor. 5. Unscrew the sensor from the Fuel Rail.


1. Lubricate the O-ring on the Fuel Temperature

Sensor with a light coat of Vaseline or petro-leum jelly. Do not contaminate the tip of the sensor.

The HEGO is sensitive to silicone based products and can become contaminated. Avoid using silicone sealers/lubricants on any fuel or exhaust related components.

2. Install the sensor into the Fuel Rail. Torque

to 6-7.5 ft. lbs. (8-10 Nm). DO NOT EXCEED 7.5 ft. lbs. (10 Nm).

3. Reconnect the electrical connector to the Fuel Temperature Sensor.

4. Reconnect the negative battery cable. 5. Open valve on the LPG tank. 6. Turn ignition key to ON and check for leaks at

the inlet and outlet fittings using a commercial grade soapy solution or an electronic leak de-tector. If leaks are detected make repairs.

7. Start the vehicle and let run until it reaches

normal operating temperature. 8. If a DTC code is found, refer to the Electrical

Section for further diagnosis. VIII. ENGINE COOLANT TEMPERATURE SENSOR (ECT)

REMOVAL PROCEDURE 1. Disconnect the negative battery cable. 2. Drain the coolant. 3. Locate the ECT just below the thermostat

housing . 4. Remove electrical connector from the ECT.

The coolant may be hot. Use caution when removing hose(s) to prevent contact.


1. Apply a light coat of Loctite 567 or equivalent

pipe thread sealant on the threads of the ECT.

2. Install the ECT into the engine and torque until tight.

3. Connect the ECT electrical connector. 4. Refill the cooling system. 5. Reconnect the negative battery cable. 6. Start the vehicle and let run until it reaches


Section for further diagnosis. 8. Allow the engine to cool, check coolant level

and add coolant if necessary.

242

IX. HEATED EXHAUST GAS OXYGEN SENSOR

(HEGO)

REMOVAL PROCEDURE 1. Disconnect Negative battery cable. 2. Locate the Oxygen Sensor. 3. Disconnect the Oxygen sensor electrical con-

nector.

HEGO and Fitting

4. Using an Oxygen Sensor socket, remove the Oxygen Sensor.


IMPORTANT Before installing the Oxygen sensor lubricate threads with anti-seize compound GM P/N 5613695 or equivalent. Avoid contaminating sen-sor tip with compound. 1. Install Oxygen Sensor. 2. Reconnect electrical connector to the Oxygen

Sensor. 3. Reconnect the negative battery cable. 4. Start the vehicle and let run until it reaches

normal operating temperature and is in closed loop.


X. THROTTLE BODY AND/OR GASKET

REMOVAL PROCEDURE 1. Disconnect the negative battery cable. 2. Remove the air intake. 3. Remove Throttle Body electrical connector. 4. Remove four Screws that secure the Throttle

Body. 5. Remove the Throttle Body and the Gasket.


1. Inspect Throttle Body Gasket. Replace if ne-cessary.

2. Place Throttle Body and Gasket on the Intake Manifold plenum, align and secure with four Screws. Torque to 7-9 ft.lbs. (9.5-12.2 Nm).

3. Connect electrical connector. 4. Reconnect negative battery cable. 5. Start Engine. Verify correct operation in all

throttle ranges. 6. Using the DST, clear DTC information from

the ECM. 7. Turn the ignition OFF and wait 30 seconds. 8. Start the vehicle and let run until it reaches


Section for further diagnosis. XI. REGULATOR

Regulator REMOVAL PROCEDURE

1. Relieve the LPG fuel system pressure. Refer


2. Disconnect Negative battery cable. 3. Remove the electrical connector on the Shu-

toff Valve. 4. Remove the Fuel Hose from the regulator. 5. Remove the LPG Fuel Line at the flare fitting

attached to the Shutoff Valve.

243

A small amount of fuel may still be present in the fuel line. Use gloves and proper eye protection to prevent burns. If liquid fuel continues to flow from the connections when removed, make sure the manual valve is fully closed.

6. Clamp both Coolant Hoses as close to the

Regulator as possible. 7. Remove Coolant hoses.


8. Remove the Bolt securing the Regulator.


1. Secure Regulator with Bolt. Torque to 12.5

ft.lbs. (17 Nm). 2. Attach the LPG Fuel Line at the flare fitting

attached to the Shutoff Valve. 3. Reconnect LPG Fuel Line (to Fuel Rail). 4. Connect Coolant Lines secure with hose

clamps. Remove clamps from hoses (if used during removal).

5. Connect the fuel supply line (from tank). 6. Slowly open LPG Tank Valve. IMPORTANT: The fuel cylinder manual valve contains an Excess Flow Check Valve. Open the manual valve slowly to prevent activating the Excess Flow Check Valve. 7. Reconnect negative battery cable. Turn igni-

tion key to ON and check for leaks at the inlet and outlet fittings using a commercial grade soapy solution or an electronic leak detector. If leaks are detected make repairs.

8. Start engine and check for fuel and coolant leaks. If leaks are detected make repairs.

9. Check for MIL illumination. 10. Run engine to normal operating temperature

and turn key to OFF. 11. Check coolant level and add coolant if neces-

sary.

XII. CHECKING/DRAINING OIL BUILD-UP IN THE LOW PRESSURE REGULATOR

During the course of normal operation oil or “heavy ends” may build inside the secondary chamber of the Regulator. These oil and heavy ends may be a result of poor fuel quality, conta-mination of the fuel, or regional variation of the fuel make up. A significant build up of oil can af-fect the performance of the secondary diaphragm response. The Recommended Maintenance Schedule found in this section recommends that the oil be drained periodically. This is the mini-mum requirement to maintain the emission warranty. More frequent draining of the Regulator is recommended for special situation where subs-tandard fuel may be a problem. IMPCO recommends the Regulator be drained at every engine oil change if contaminated or substandard fuel is suspected or known to be have been used or in use with the emission complaint fuel system. This is known as special maintenance, and failure to follow this recommendation may be used to de-ny a warranty claim. IMPORTANT: Draining the Regulator when the engine is warm will help the oils to flow freely and permit easier removal from the Regulator. To drain the Regulator, follow the steps below: 1. Move the equipment to a well ventilated area

and ensure no external ignition sources are present.

2. Turn off LPG Valve and Relieve the LPG fuel system pressure. Refer to XVIII. LPG FUEL SYSTEM PRESSURE RELIEF.

3. Disconnect Negative battery cable.

A small amount of fuel may still be present in the fuel line. Use gloves and proper eye pro-tection to prevent burns. If liquid fuel continues to flow from the connections when removed, make sure the manual valve is fully closed.

4. Remove the plug on the Regulator under the

lower coolant port. 5. Place a small receptacle in the engine com-

partment to catch any liquid that may come

244

out of the Regulator. 6. Inspect the Regulator for any large dried par-

ticles and remove. Use a safety solvent to remove any build up.

Use only Safety Solvents for the cleaning of the regulator and its components. Sol-vents such as carburetor or brake cleaners may damage gaskets, seals, O-rings, di-aphragms or other non-metal components.


7. Reinstall the Plug. Torque until tight. 8. Connect negative battery cable. 9. Open Valve on LPG tank. IMPORTANT: The fuel cylinder manual valve contains an Excess Flow Check Valve open the manual valve slowly to prevent activating the Excess Flow Check Valve.

10. Turn Key ON. Check for leaks at the inlet and outlet fittings using a soapy solution or an electronic leak detector. If leaks are detected make repairs.

11. Start engine and check for leaks at all ser-viced fittings. If leaks are detected make repairs.

12. Dispose of any drained material in safe and proper manner.

XIII. FUEL FILTER ELEMENT (HIGH PRESSURE) REMOVAL PROCEDURE

1. Relieve the LPG fuel system pressure. Refer to XVIII. LPG FUEL SYSTEM PRESSURE RELIEF.

2. Disconnect negative battery cable.

A small amount of fuel may still be present in the fuel line. Use gloves and proper eye pro-tection to prevent burns. Make sure the manual valve is fully closed.

Regulator, showing filter related components.

3. Disconnect the fuel inlet and outlet lines from

the LPG Regulator. 4. Remove the fuel inlet fitting (7) and O-ring (6). 5. Remove the plastic body (5), foam filter (4),

paper filter element (3), and filter gasket (2). 6. Remove the screws (5), fuel outlet fitting (4)

O-ring (3), and filter (2). Discard O-ring and fil-ter. INSTALLATION PROCEDURE

1. Install new filter (2) in port for fuel outlet fitting. Install new O-ring (3) and fuel outlet fitting (4).

2. Install retaining screws (5) for fuel outlet fitting (4). Tighten screws to 2 to 3 N•m (17.7 to 26.55 in. lb.).

245

3. Install the filter gasket (6), new paper filter element (7), new foam filter (8), and plastic body (9).

4. Install the fuel inlet fitting (11) and O-ring (10). Tighten to 18 to 20 N•m (13.3 to 14.75 ft.lbs.).

5. Connect the fuel inlet line to the LPG Regula-tor.

6. Connect the negative battery cable. 7. Slowly open the fuel valve on tank.

IMPORTANT: The fuel cylinder manual valve contains an Excess Flow Check Valve. Open the manual valve slowly to prevent activating the Excess Flow Check Valve. 8. Turn the key to the ON position and back to

the OFF position to pressurize the fuel sys-tem. Check for leaks.

9. Check for leaks at connections by using soapy solution or electron leak detector. If leaks are detected, make proper repairs.

10. Start engine and ensure correct operation in all throttle ranges.


XIV. LOCK-OFF SOLENOID AND CARTRIDGE 1. Relieve the LPG fuel system pressure. Refer


2. Disconnect negative battery cable. 3. Disconnect the electrical connector from the

lock-off solenoid. 4. Remove the nut and solenoid from the car-

tridge 5. Remove the cartridge from the LPG Regula-

tor. INSTALLATION PROCEDURE

1. Install new cartridge into LPG Regulator. Tigh-ten cartridge to 16 to 24 N•m (11.8 to 17.7 ft.lbs.).

2. Install solenoid and nut onto cartridge. Tigh-ten nut to 7.85 N•m (69.5 in.lbs.).

3. Connect electrical connector to solenoid. 4. Connect the negative battery cable.

IMPORTANT: The fuel cylinder manual valve contains an Excess Flow Check Valve. Open the manual

valve slowly to prevent activating the Excess Flow Check Valve.

5. Slowly open the fuel valve on tank. 6. Turn the key to the ON position and back to

the OFF position to pressurize the fuel sys-tem. Check for leaks.


8. Start engine and ensure correct operation in all throttle ranges.


XV. FUEL RAIL



2. Disconnect the negative battery cable. 3. Remove the pin securing the fuel inlet hose,

then remove fitting from the fuel rail. 4. Remove Fuel Pressure Sensor electrical con-

nection. 5. Remove two bolts securing the Fuel Rail. 6. Carefully pull the rail flush along the Fuel Rail

and away from the Fuel Injectors. 7. If rail is to be replaced, remove the Fuel Pres-

sure Sensor. Refer to VII. FUEL PRESSURE SENSOR.


1. Install Fuel Pressure Sensor, if removed Refer

to VII. FUEL PRESSURE SENSOR. 2. Lubricate Fuel Injector O-rings with petroleum

jelly or Vaseline.

246


3. Carefully place the Fuel Rail over the injec-

tors, sliding along the Fuel Rail Bracket. Ensure the Fuel Injectors and O-rings are properly seated.

4. Align holes on Fuel Rail with holes in the bracket and insert screws. Torque to 7-9 ft.lbs. (9.5-12.2 Nm).

5. Connect Fuel Pressure Sensor electrical con-nection.

6. Insert fuel inlet port fitting and secure with pin. 7. Reconnect negative battery cable. Turn igni-


8. Start engine and check leaks. If leaks are detected make repairs.

9. Check for MIL illumination. XVI. FUEL INJECTOR



2. Disconnect the negative battery cable. 3. Remove the Fuel Rail. Refer to XV. FUEL

RAIL. 4. Remove Injector electrical connector. 5. Remove Clip Retaining Fuel Injector (connect-

ing it to the Injector Adapter).

The Fuel Injectors are held in place with an internal "C" ring. When removing the fuel in-jectors, pull the injectors straight out. Do not pry the injectors with a screwdriver or prybar, as this can damage the injectors or injector adapters.

6. Remove Injector.


1. Inspect the O-rings on the Injector and Injector Adapter and replace if necessary. Lubricate with Vaseline or petroleum jelly.


2. Install the Fuel Injectors into the Fuel Injector

247

Adapters. Push the Injectors into the Adapters using hand pressure only.

3. Install the Clip Retaining Fuel Injector (con-necting it to the Injector Adapter).

4. Ensure all Injectors are properly aligned to mate to the Fuel Rail.

5. Install Fuel Rail. Refer to X. FUEL RAIL 6. Connect the electrical connector(s) to the fuel

injector(s). Verify that the connectors click/lock into place.

7. Connect the fuel line to the fuel rail. 8. Reconnect negative battery cable. Turn igni-



10. Check for MIL illumination. XVII. FUEL INJECTOR ADAPTERS REMOVAL PROCEDURE

Fuel Injector Adapter 1. Relieve the LPG fuel system pressure. Refer


2. Disconnect the negative battery cable. 3. Remove the Fuel Rail. Refer to X. FUEL

RAIL. 4. Remove the Injector(s). Refer to XI. FUEL

INJECTOR. 5. Remove the Fuel Injector Adaptor(s) from the

Intake Manifold. 6. Place tape or rag over the opening in the In-

take Manifold to prevent dirt or debris from en-tering the engine, possibly causing permanent engine damage.

INSTALLATION PROCEDURE 1. Lubricate the O-rings on the Fuel Injector

Adapter with Vaseline or petroleum jelly and place back on the Intake Manifold, ensuring it is properly seated.


2. Install Injector of top of Adapter. Refer to XI.

FUEL INJECTOR. 3. Install Fuel Rail. Refer to X. FUEL RAIL. 4. Reconnect negative battery cable. Turn igni-



6. Check for MIL illumination.

248

XVIII. LPG FUEL SYSTEM PRESSURE RELIEF

The LPG fuel system operates at pressure up to 21.5 bar (312 psi). To minimize per-sonal injury, relieve the LPG fuel system pressure before servicing the LPG fuel sys-tem components.

1. Close the LPG fuel tank manual shut-off valve

(MSV). 2. Start and run the vehicle until the engine stalls

from lack of fuel. 3. Turn the ignition switch to OFF. 4. Disconnect the negative battery cable.

Residual vapor pressure will be present in the fuel system. Ensure the work area is well ventilated before disconnecting any fuel line.

Never use an open flame of any type to check for LPG leaks.

IMPORTANT Always inspect the LPG fuel system for leaks after performing service. Check for leaks at the fittings of the serviced or replaced component. Use a commercially available liquid leak detector or an electronic leak detector. When using both me-thods, use the electronic leak detector first to avoid contamination by the liquid leak detector XIX. CRANKCASE VENTILATION SYSTEM INSPECTION/DIAGNOSIS RESULTS OF INCORRECT PCV OPERATION A plugged positive crankcase ventilation (PCV) orifice or hose may cause the following conditions: Rough or unstable idle Stalling or low idle speed

Oil leaks Oil in the air cleaner Sludge in the engine A leaking PCV orifice or hose may cause the fol-lowing problems: Rough Idle Stalling High idle speed FUNCTIONAL CHECK Any blow-by in excess of the system capacity, from a badly worn engine, sustained heavy load, etc., is exhausted into the air cleaner and is drawn back into the engine. Proper operation of the crankcase ventilation sys-tem depends on a sealed engine. If irregular oil flow or dilution is noted and the crankcase ventila-tion system is functioning properly, check the engine for another possible cause. Correct any of these problems first. If an engine is idling rough, inspect for a clogged PCV orifice, a dirty vent filter, air cleaner element, or plugged hose. Replace any faulty items found. Use the following procedure: 1. Remove the PCV hose from the rocker arm

cover. 2. Operate the engine at idle. 3. Place your thumb over the end of the hose in

order to check for vacuum. If there is no va-cuum at the hose end, inspect for plugged hoses and/or clogged or damaged manifold vacuum port.

4. Turn the engine OFF. 5. Inspect the PCV orifice in the valve cover for

debris or blockage. Clean with carburetor cleaner as necessary.

XX. COOLANT HOSE

REMOVAL PROCEDURE

1. Stop engine. 2. Drain coolant.

249


3. Remove clamps from each end of the Hose

and remove Hose. INSTALLATION PROCEDURE

IMPORTANT Coolant hoses are specifically designed for their application. DO NOT use hose material or length other than the OEM specified parts. DO NOT mix the inlet or outlet ends of the Hose when reinstal-ling.

1. Slide Clamps over each end of the Hose. 2. Insert Port Fittings into each end of the Hose. 3. Slide Hose Clamp to a position approximately

½” from the end of the Hose and tighten. 4. Refill with coolant. 5. Start engine and let run until it reaches operat-

ing temperature. 6. Check for leaks. If leaks are detected, make

repairs. 7. Stop engine and allow to cool. Check coolant

level and add coolant as necessary. XXI. FUEL VAPOR HOSE

REMOVAL PROCEDURE

1. Relieve the LPG fuel system pressure. Refer


2. Disconnect negative battery cable. 3. Remove Retaining Clips securing Port Fittings

on both ends and remove with Hose attached. 4. Remove Hose Clamps. 5. Remove Port Fittings from Hose.


IMPORTANT Hoses are designed for specific applications. DO NOT use Hose material or length other than spe-cified by the OEM. DO NOT mix the inlet or outlet ends of the Hose when reinstalling.

INSTALLATION PROCEDURE 1. Slide Hose Clamps over each end of the Fuel

Hose. 2. Insert Port Fittings into each end of the Hose. 3. Slide each Hose Clamp to a position approx-

imately ½” from the end of the Hose and tighten.

4. Lightly lubricate new O-ring with Vaseline or petroleum jelly prior to installation.


5. Reinstall Hose at both ends and secure using Retaining Pins.

6. Reconnect negative battery cable. 7. Open LPG tank valve. 8. Turn Key to the ON position for several

seconds, then turn back to OFF. Check for leaks at the inlet and outlet fittings using a soapy solution or an electronic leak detector. If leaks are detected, make repairs.

9. Start engine and check for leaks. 10. If a DTC code is found, refer to the Electrical

Section for further diagnosis.

250

XXII. FUEL VAPOR PORT FITTING

REMOVAL 1. Relieve the LPG fuel system pressure. Refer


2. Disconnect negative battery cable. 3. Remove retaining clip securing the Port Fitting

in the port and remove. 4. Loosen Hose Clamp securing the Port Fitting

in the Hose and pull Port Fitting from hose. INSTALLATION

IMPORTANT Port Fittings are designed for specific applications, DO NOT any other adapter or fitting other than the part specified by the OEM. 1. Slide Hose Clamp over the Hose. 2. Insert Port Fitting into hose. 3. Slide Hose Clamp over the end of the Hose

and tighten. 4. Lightly lubricate O-rings on the Port Fitting

with Vaseline or petroleum jelly.


5. Reinstall Hose Port into port and secure using

a Retaining Pin. 6. Reconnect negative battery cable. 7. Open LPG tank valve.

IMPORTANT: The fuel cylinder manual valve contains an Excess Flow Check Valve. Open the manual valve slowly to prevent activating the Excess Flow Check Valve. 8. Turn Key to the ON position for several

seconds, then turn back to OFF. Using a liq-uid or electronic leak detection tool, inspect the REGULATOR, fuel hoses and all serviced fittings for leaks.

9. Start engine and check for leaks. XXIII. REGULATOR PRESSURE CHECK

1. Refer to XXIV. LPG FUEL RAIL PRESSURE CHECK to check the Regulator outlet pres-sure.

XXIV. LPG FUEL RAIL PRESSURE CHECK 1. Relieve the LPG fuel system pressure. Refer


2. Disconnect the negative battery cable. 3. Remove the Fuel Pressure Sensor. Refer to

VII. FUEL TEMPERATURE/PRESSURE SENSOR.


4. Connect the test fitting, Hose and Gauge. 5. Open LPG Tank Valve. 6. Connect negative battery cable. 7. Turn ignition to ON and note value on gauge. 8. Relieve the LPG fuel system pressure. Refer


9. Remove Gauge. Install Fuel Temperature Sensor. Refer to VII. FUEL TEMPERATURE/PRESSURE SENSOR.

251

The HEGO is sensitive to silicone based products and can become contaminated. Avoid using silicone sealers/lubricants on any fuel or exhaust related components.

10. Reconnect negative battery cable. 11. Turn key to ON. 12. Check for leaks. If leaks are detected, make

repairs. XXV. LPG FUEL SYSTEM LEAK TEST 1. Use a commercially available liquid leak detec-

tor or an electronic leak detector and follow the manufacturer’s instructions.

IMPORTANT When using both methods, use the electronic leak detector first to avoid contamination by the liquid leak detector. XXVI. RESTRICTED EXHAUST SYSTEM

DIAGNOSIS

PROCEDURE: 1. Stop Engine. Carefully remove the HEGO. 2. Install Exhaust Back Pressure Test Gauge

(J35314-A) in place of the HEGO. 3. With the engine idling at normal operating

temperature, observe the exhaust system back pressure reading on the gauge. Reading should not exceed 8.6 kPa (1.25 psi).

4. Increase engine speed to 2000 RPM and ob-serve gauge. Reading should not exceed 20.7 kPa (3 psi).

5. If the back pressure at either speed exceeds specification, a restricted exhaust system is indicated.

6. Inspect the entire exhaust system for a col-lapsed pipe, heat distress or possible internal catalytic converter failure.

7. If there are no obvious reasons for the exces-sive back pressure, the catalytic converter is likely damaged and should be replaced.

8. Check for MIL. If a DTC code is found, refer to the Electrical Section for further diagnosis.

1. Back Pressure Gauge 2. Heated Exhaust Gas Oxygen Sensor

(HEGO 1--Sensor between the engine and catalytic converter).

3. Exhaust Pipe/Muffler

Exhaust Back Pressure Test

XXVII. CATALYTIC CONVERTER

REMOVAL PROCEDURE 1. Remove the Catalytic Converter using the

OEM end product processes

INSTALLATION PROCEDURE IMPORTANT The Catalytic Converter is specifically designed to meet the emission control of the certified engine. Use only the OEM specified part. Install the Cata-lytic Converter using the OEM end product processes. 1. Start engine 2. Check for any DTC codes and clear 3. Verify engine is in closed loop and no MIL

lights are present. 4. If a DTC code is found, refer to the Electrical

Section for further diagnosis.

252

XXVIII. VACUUM LINE

REMOVAL PROCEDURE 1. Remove the Vacuum Line from each fitting.


IMPORTANT DO NOT use a hose other than the OEM specified part. 1. Reinstall the Fuel Vapor Hose to each fitting. 2. Start engine and check for leaks using a soa-

py solution or an electronic leak detector. If leaks are detected make repairs.

XXIX. LPG FUEL CONTROL SYSTEM CHECK 1. The fuel system can be thoroughly diagnosed

by use of the DST tool. See section DIAGNOSTIC SCAN TOOL.

XXX. CAMSHAFT POSITION SENSOR REMOVAL PROCEDURE 1. Disconnect negative battery cable. 2. Label Spark Plug Wires with matching Distribu-

tor Cap numbers and remove by pulling and twisting each spark plug wire boot ½ turn.

3. Remove Ignition Coil wire. 4. Remove the electrical connector from the

base of the Distributor. 5. Remove the two Screws that hold the Distribu-

tor Cap to the housing and remove Cap. 6. Remove the Rotor Screws. 7. Turn the engine crankshaft to align the square

slot in the reluctor wheel with the Cam Sensor. 8. Remove the two screws securing the CMP

Sensor 9. Remove the Camshaft Sensor from the Dis-

tributor. INSTALLATION PROCEDURE IMPORTANT Do no not reuse the old Distributor Cap, Rotor or Cam Sensor Screws. 1. Mount Camshaft Sensor on Distributor and

secure with new Screws. Torque to 19 in.lbs. (2.2 Nm)

2. Install the Rotor on the reluctor wheel and se-cure with new Rotor Screws. Torque to 18 in.lbs. (2.0 Nm).

3. Install new Rotor Cap and secure with new Screws. Torque to 21 in.lbs. (2.4 Nm)

4. Connect the sensor harness connector. 5. Connect Spark Plug wires to the Distributor

Cap, ensuring the wires are connected to the correct cylinder. NOTE that the firing order is 1-3-4-2. Refer to the IGNITION SYSTEM SPECIFICATIONS in the Appendix for addi-tional information.

6. Start engine. If a DTC code is found, refer to the Electrical Section for further diagnosis.

XXXI. FUEL FILTER REPLACEMENT NOTE: The following instructions only include the low pressure LPG Vapor Fuel Filter and not the high pressure liquid LPG fuel filter on the regula-tor. Refer to XIII. FUEL FILTER ELEMENT (HIGH PRESSURE) for the high pressure filter on the Regulator.

Low Pressure LPG Vapor Fuel Filter

1. Move the equipment to a well ventilated area

and verify that sparks, ignition and any heat sources are not present.

2. Relieve the LPG fuel system pressure. Refer to XVIII. LPG FUEL SYSTEM PRESSURE RELIEF.

3. Disconnect negative battery cable.

A small amount of fuel may still be present in the fuel line. Use gloves and proper eye pro-tection to prevent burns. Make sure the manual valve is fully closed.

4. Remove the clamps securing the fuel hoses to

the fuel filter. 5. Remove the hoses connected to the fuel filter. 6. Loosen the Cushioned Clamp securing the

253

Fuel Filter and slide out. 7. Discard Fuel Filter.


1. Slide the Fuel Filter inside the cushioned clamp and tighten.

2. Place clamps over hoses. 3. Connect hoses to the Fuel Filter. 4. Tighten hose clamps on Fuel Filter. 5. Retighten clamp securing Fuel Filter. 6. Connect negative battery cable. 7. Open LPG fuel valve on tank. IMPORTANT: The fuel cylinder manual valve contains an Excess Flow Check Valve. Open the manual valve slowly to prevent activating the Excess Flow Check Valve. 8. Turn Key to ON. Check for leaks at the inlet

and outlet fittings, and the filter housing end connection using a soapy solution or an elec-tronic leak detector. If leaks are detected make repairs.

9. Start engine and check for leaks once more. XXXIV. PCV

REMOVAL 1. Remove Hose Clamp on Hose connected to

PCV and remove Hose. 2. While gently rocking back and forth, pull PCV

from its mounting gasket and remove.

255

LPG Parts Diagram

256

THROTTLE BODY ASSEMBLY

257

MIXER AND THROTTLE BODY ASSEMBLY

Item # Description Qty IMPCO

Part Number

1 Screw, Hex Sck Cap 4 S1-30295-0655 2 Washers, Conical Spring 6mm 4 W1-31039-006 3 Throttle Body 1 A7-324 4 Gasket, Throttle Body 2 A7-245 5 Bracket, Fuel Rail Mount 1 B4-51980-001

258

FUEL RAIL & INJECTORS

259

FUEL RAIL & INJECTORS


Part Number

1 Sensor, Fuel Rail Pressure 1 A7-473

2 Screw, Hex Flange M6-1.0 x 35 mm 2 P1-30559

3 Fuel Rail, 3.0L 1 R8-51549-001

4 Pin, Retaining 1 P1-30559

5 O-Ring, Inlet 4 A7-657

6 Spacer, O-ring 4 A7-656

7 Injector, LPG/CNG 4 A7-654

8 O-ring, Adapter 4 A7-655

9 Adapter, Fuel Injector 4 A4-51981-001

10 O-ring, FKM-75 .362 ID 4 GMN-033

260

REGULATOR ASSEMBLY

261

REGULATOR ASSEMBLY


Part Number

1 Regulator Assy (Fully Assembled with all parts) 1 A7-434 Filter Kit (Includes 2, 6, 7, 8, 9) 1 A7-170 Outlet Fitting Service Kit (Includes 3 & 4) 1 A7-172 5 Screw Kit (Includes 3 screws) 1 A7-176 Inlet Fitting w/O-Ring (Includes 10 & 11) 1 A7-171

12 Drain Plug & O-ring Kit (Includes 12 & O-ring) 1 A7-173 13 Lock-Off Assembly 1 A7-175

262

HOSE ASSEMBLIES COOLANT/VACUUM/FUEL

263

HOSE ASSEMBLIES COOLANT/VACUUM/FUEL

Item #

Description Qty IMPCO

Part Number 1 Fitting, Port 1 AF4-50733-001 2 Clamp, Oetiker 2 C1-51552-07-170 3 Hose, Vacuum 1 H1-19231-001 4 Hose 3/8” ID Fuel/Oil 1 H1-19231-004 5 Hose, 5/8” Fuel/Oil 1 H1-19231-006 6 Clamp, Ear Oetiker 2 C2-51552-05-113 7 Pin, Retaining 1 P1-30559

8 Clamp, Worm Drive 4 0130845 9 Clamp, Oetiker 4 C1-51552-07-256 10 Hose, 5/8” ID Fuel/Oil 1 H1-19231-006 11 Bracket, Vapor Filter 1 A10-167 12 Filter, LPG Vapor 1 A8-367 13 Hose, Formed Gate 1

H1-50599-001 14 Hose, Formed Gate 1 15 Clamp, Worm Drive 1 A10-169 16 Bolt, M8 x 1.25 x 25 2 1510113 17 Nut, Hex 2 97330010

264

THERMOSTAT & HOUSING

265

THERMOSTAT & HOUSING

Item # Description Qty Part Number GM Part Number

1 Bolt 2 90328100 09424320 2 Thermostat Housing 1 7142071 14096853 3 Gasket, Thermostat Housing 1 7140310 10105135 4 Thermostat 1 7140340 10220957

266

ENGINE CONTROL MODULE

267

ENGINE CONTROL MODULE

Item #

Description Qty IMPCO Part Number

1 ECM, Liugong 1 A11-173

268

SENSORS

4

1

3

6

5

2

7

269

SENSORS

Item # Description Qty. Used

IMPCO Part Number

GM Part Number

1 HEGO 1 S8-50328-001 2 Crank Sensor 1 S8-51822-001 12567712 3 Sensor, TMAP 1 E1466001 4 Oil Pressure Switch 1 S10-50352-001 5 Adapter, Oil Pressure Switch 1 7242360 6 Coolant Temp Switch 1 7144790 7 Adapter, Coolant Switch 1 7176570-06

270

DISTRIBUTOR

271

DISTRIBUTOR

Item # Description Qty. Part Number GM

Part Number 1 Distributor 1 93442429 93442429 2 Distributor Cap 1 89060454 89060454 3 Rotor 1 7241620 10467546 4 Module/Sensor 1 7245370 10485432

272

FUSE BOX & BRACKET

273

FUSE BOX & BRACKET

Item # Description Qty. Part Number

1 Screw, Hex M4 x 16mm 4 S1-30295-0416 2 Washer, Split Lock M4 4 W1-1988-003 3 Fuse Box Cover 1 C1-52520-001 4 Bracket, ECM 1 B4-51789-001 5 Screw, Hex Flange 2 90325088 6 Seal, Fuse Box 1 S3-52522-001

274

IGNITION COIL

275

IGNITION COIL


1 Coil, Ignition 1 7245530

276

MANIFOLDS

277

MANIFOLDS


1 Gasket, Int/Ext 1 7152170 2 Manifold, Exhaust GM 3.0L 1 7152150 3 Stud, 3/8-16 x 2” 2 S3-50596-001 4 Bolt, Socket Head 3/8 x 16 Grade 8 4 90368100 5 Washer, Belleville 3/8” 8 W1-50595-037 6 Screw, Hex Flange M5-0.8 8x8 4 S1-50237-20-0508 7 Nut, Serrated 2 N1-30876-037 8 Washer, 3/8 Type A Hard 4 92300101 9 Screw, Hex Flange M6 x 12mm 8 S1-30871-02-0612 10 Screw, Hex Flange M6-1.0x x 16mm 3 S1-30871-02-0616 11 Screw Hex Flange M6-1.0 x 12mm 5 S1-50237-02-0620 12 Shield, Heat-GM 3.0L 2 Piece 1 7152160 13 Heat Shield, RB Exhaust 1 G4-50067-001 14 Heat Shield, Alternator 3.0L 1 G4-50068-001 15 TMAP Sensor 1 E1466001 16 Fitting, 1/8 NPT 3/8 Hose Brass 1 2H-103B 17 Fitting, 1/8 NPT .19 ID Hose 1 F4-4 18 Bracket, Maxifuse Mount 1 B4-51889-001 19 Gasket, Exhaust Flange 1 7152175 20 Strap, Cnvlt Cdt 13mm 2 S17-51979-001 21 Sensor, O2 1 S8-50328-001

278

WIRE HARNESS/FUSES/FUSE BOX COVER

Fuse Box Layout

4

279

WIRE HARNESS/FUSES/FUSE BOX COVER

Item # Description Qty Part Number Manufacturer Part

Number

1 Cover 1 Littelfuse 1520007Z 2 Fuse 70A 1 1054112 Littelfuse 299070 3 Fuse Holder 1 Littelfuse 1520004Z 4 Wire Harness, 4 Cyl 1 AW-50727-001

Auxiliary 10A Minifuse 1 914584 Littelfuse 297010 Power Fuse 20A Minifuse 1 7381270 Littelfuse 297020 Starter Fuse 20A Minifuse 1 7381270 Littelfuse 297020

VSW 10A Minifuse 1 914584 Littelfuse 297010 Starter Relay Starter Relay 1 885014 3011CCR1U0112VDC Power Relay Power Relay 1 885014 3011CCR1U0112VDC

Shut Off Valve Relay

Lock Off 1 885014 3011CCR1U0112VDC

280

PCV VENT & VALVE

281

PCV VENT & VALVE

Item # Description Qty Part Number GM Part Number

1 Vent, Elbow 1 F4-51936-001 06487779 2 Grommet oil filter cap 1 G3-51937-001 14050440 3 PCV 1 V3-51806-001 06487779 4 Grommet, PCV Valve 1 7120140 14001875

282

MISCELLANEOUS ENGINE

283

MISCELLANEOUS ENGINE

Item # Description Qty Part Number

1 Engine, MY 2011-2010GM 3.0L 1 7044670 2 Sensor, Crank 1 S8-51822-001 3 Plug, 3/8” NPT Socket Head Brass 1 P3-12 4 Fitting, Pipe Thread Reducer 1 7176570-06 5 Oil Filter PF454 1 7110851 6 Plug ½-14 NPT 1 7242360 7 Switch, Oil Pressure 1 S10-50352-001 8 Spark Plug, R44LTS 4 E10-50075 9 Plug, 14mm Fuel Rail Port 4 P3-50597-001 10 Fitting, 1/2NPT 5/8 NIP Brass 1 F4-17920 11 Strap, Lifting Eye 1 7010130 12 Screw, Hex Flange 3/8-16 x 1 1 90325100

284

ALTERNATOR

285

ALTERNATOR


1 3/8”-16x1-1/2” Bolt Hx GR5 2 90305150 2 Washer, Lock 3/8” 15 93300000 3 Washer, Flat 3/8” 5 92300000 4 3/8-16x1 ¼” bolt Hx Gr5 2 90305125 5 5/16-18x1” Bolt Sched Grd 8 4 90268100 6 Sapcer, Fan Mount 3.0L 1 7143890 7 5/16-18x1 ¼” Bit Hx Gr5 1 90205125 8 Washer, Lock, M8 1 93200000 9 Bracket, Alternator 1 7144570 10 Alternator, 7SI 1 7244700 11 Nut, Hex Flange Serrated M5 x 1.0 2 N1-30876-M06 12 Nut, 3/8”-16 Grade 5 1 95300000 13 Spacer, Alternator Brkt 1 7244570 14 Bracket, Alt Lower 1 7244560 15 Bolt, Hex 3/8-16 x 4” Grade 5 1 90305400 16 Bolt, M8-1.25 Hx Head Grd 10.9 1 98333025 17 Washer, Lock, Med, M8, Zn 1 93930000 18 Washer, Flat Heavy 5/6” 1 92200020 19 Pulley, Water Pump 1 7144040 20 Pulley, Crankshaf 1 7071620 21 3/8-24x2” bolt Hx Gr5 1 90315200 22 5/16”-18 x ¾” Grade 5 8 90215075 23 3/8-16x3-1/2 Blt Sched Gr5 1 7144160 24 ASM Fan Hub 3.0L 1 7144220 25 Pulley Twin Belt 1 7144130 26 Ring Retaining OD 0.669 1 7144030 27 Pully ASM P/B Boos Pump Idler 1 7030110 28 Bracket Tensioner 1 7144000 29 Pulley, Water Pump-Mod 1 7144040 30 Bracket Fan Tensioner MTG 1 7143881

286

STARTER

287

STARTER


1 Bolt 2 7242530 2 Nut Hex M5 x 0.8 Brass 1 97111000 3 Washer, Lock Bronze 1 93003000 4 Nut, Hex M8 x 1.25 Brass 1 97331000 5 Washer, lock med M8 Zn 1 93930000 6 Starter Motor 1 7244520 7 Bracket, Starter 2kW 3.0L 1 B4-52110-001 8 Nut Hex #10-24 1 95000000 9 Washer, Lock #10 Med 1 93000000 10 Washer Flat #10 1 92000000 11 5/16-18 ¾” Bolt Hex Gr5 1 9205075 12 Washer, Loc, Med 5/16 1 93200000 13 Washer, flat, SAE, 5/16” 1 92200000

288

TOOL KIT & ACCESSORIES

1 2 3 4 5

6 7 8 9 10

11 12 13 14

Standard Oetiker Pliers, IMPCO P/N 14100037 and Injector Test Lamp OTC-6023 (not included in any IMPCO ITK kit)

289

TOOL KIT, IMPCO P/N ITK-4

Item #

Description Qty. Used

IMPCO Part Number

1 Test Kit Gauge 0-5 PSI (2-5205) 1 TG-005 2 Test Kit-Gage 0-10" WC (2-5010) 1 TG-010 3 Hose, 3/16" Id Vacuum, Bulk 1.5’ H1-11 4 Harness, Adapter Gen 2 DLC to Gen 1 DLC 1 E1557400

5 Fitting Assembly, Test Cap (System II LPR

Secondary Pressure Test Adapter) 1 AF4-31105

6 Fitting, 1/8 NPT 3/16Hs Nip Brass 2 F4-4 7 Assembly, Fitting Test Cap 3/4 1 AF4-50254-002 8 Pin, Retainer 10 P1-30559 9 Case, Metal, 14.25 x 9 x 4.25 1 C9-50724-001 10 Fitting, 1/8 NPT 1/4Hs El Nylon 2 F4-8 11 Tool, 20IPR Torx-Plus Bit 1 T7-50172 12 Fitting, ¼ UNF, ¼ HS Vac Nip 1 F4-2

13 Gauge, Test Fuel System 1 TG-31119-001 14 ASM, CAN Dongle (ECOM Cable) 1 E2046002

290

The follow parts manual includes GM Service parts and their GM part numbers for the 3.0L 2011 engine. The IMPCO part number for the complete service block is:

3.0L (GM Engine Code BL3)

7044670

292

3.0L UPPER

293

3.0L UPPER


1 Cap, Oil 1 93802366 2 Bolt, Vlv 5 09439930 3 Reinforcement, Vlv Rkr Arm Cvr 5 03877670 4 Cover, Vlv Rkr Arm 1 02770089 5 Gasket, Vlv Rkr Arm Cvr 1 14096154 6 Rotator, Vlv 4 14042575 7 Key, Vlv Stem 16 24503856 8 Nut, Vlv Rkr Arm 8 12557390 9 Ball, Vlv Rkr Arm 8 93427660

10 Arm Kit, Vlv Rkr w/Ball 8 05723551 11 Rod, Vlv Push 8 93414888 12 Shield, Vlv Stem Oil 12 10007818 13 Stud, Vlv 8 03814692 14 Cap, Vlv Sprg 8 10038209 15 Seal, Vlv Stem Oil 8 10214034 16 Spring, Vlv 8 94666172 17 Bolt, Cyl Hd 10 10166832 18 Plug, Cyl Hd Core Hole 2 03826506 19 Gasket, Eng Cool Therm Hsg 1 10140501 20 Housing, Eng Cool Therm 1 93442430 21 Bolt, Eng Cool Therm Hsg 3 09424320 22 Lifter, Vlv 8 05232720

23 Head, Cyl Cmpl w/Valves, Springs, Re-tainers & Seals

1 93442423

24 Insert, Vlv Push Rod 8 NSS 25 Plug, Inj Hole 4 P3-50597-001* 26 Valve, Int 4 14075641 27 Valve, Exh 4 94665131 28 Gasket, Cyl HD 1 14096660

AR=As Required; NSS=Not Sold Separately; NA=Not Available

*IMPCO Part Number

294

3.0L LOWER

295

3.0L LOWER

Item # Description QtyPart Num-

ber

1 Ring Kit (STD)

4 88894219

Ring Kit (0.020” O.S.) 12361570 Ring Kit (0.030” O.S.) 14089026

2 Piston (w/Pin)(STD)4 93442974

Piston (w/Pin)(0.020” O.S.) 93419821 3 Rod Connecting (Includes 4 & 6) 4 10108688 4 Bolt, Connecting Rod (Part of 3) 8 00461372

5 Bearing Kit, Connecting Rod (STD)4 12493123

Bearing Kit, Connecting Rod (O.S. 0.001”) 12493124 6 Nut, Conn Rod (Part of 3) 1 00326312 7 Bearing, Oil Pmp Drive 8 03866766 8 Gasket W/Pmp 1 10101256 9 Pump, Water 1 88894247

10 Bolt, W/Pmp 1 09442184 11 Hub, Fan W/Pmp (Part of 9) 1 NSS 12 Washer, 6.3mm ID 3 11503663 13 Bolt, Cm/Shaft 3 09442895 14 Bolt, W/Pmp 5/16” 2 09440366 15 Key, Cm/Shft 2 00106751 16 Bolt, CM/Shaft 2 09442008 17 Washer, CM/Shf 1 10101744 18 Gear, CM/Shf 1 02771369 19 Plate Kit, CM/Shf 1 12508079 20 Ring, CM/Shf 1 00549631 21 Bearing, CM/Shf 4 14002525 22 Camshaft, Eng 1 02770015 23 Valve, Oil Filter 1 25013759 24 Pin, Cyl HD 8 00585927 25 Fitting, Oil Fltr 1 03853870

26

Bearing Kit, Cr/Shf (#1,2,3,4)(0.001” U.S.)

4

12329955 Bearing Kit, Cr/Shf (#1,2,3,4)(STD) 12329954 Bearing Kit, Cr/Shf (#5)(0.001” U.S.) 10048778 Bearing Kit, Cr/Shf (#5)(STD) 12329774

27 Key, Woodruff #9 1 00106751 28 Seal, Cr/Shft Frt Oil 1 12577710 29 Gear, Cr/Shf 1 02768986 30 Gasket, Front Engine Cvr 1 14096156 31 Cover, Eng Frt 1 03992251 32 Balancer, Cr/Shf 1 03826280


296


33 Seal, Absorber, Cr/Shf 1 NSS 34 Washer, External Tooth 1 00136857 35 Bolt, Cr/Shf Balancer 1 10126796 36 Nut, Oil Pan 10 12338130 37 Washer 10 09439510 38 Bolt, Oil Pan (1/4-20 x 1/2, 1/8 THD) 10 09442895 39 Plug, Oil Pan Drn 1 See IMPCO Catalog

40 Gasket, Oil Pan Drn Plug 1 See IMPCO Catalog

41 Pan, Oil 1 93419740 42 Bolt, Oil Pan (1/4-20 x 1/2, 1/8 THD) 14 09440033 43 Screw, RD HD Slotted 4 00133043 44 Washer 4 09439510 45 Cover, O/Pmp 1 03792507 46 Gasket O/Pmp Cover 1 03789970 47 Spring, Oil Pressure Rlf Vlv 1 03814903 48 Plug, Oil Press Rlf Vlv 1 03930824 49 Valve, Oil Pressure Rlf 1 03829433 50 Bolt, O/Pmp 3 09424877 51 Reinforcement, Eng Frt Cvr (Incl w/31) 1 NSS 52 Gasket, Oil Pan 1 14096637 53 Bolt, Eng Frt Cvr 12 09442895 54 Pump, Oil 1 14091485 55 Nozzle, Cm/Shf Gr Lub 1 03875950 56 Bracket, O/Pmp 1 03970417 57 Crankshaft 1 93442002 58 Bolt, Hex 1/4-20 x 3/4 1 09425113 59 Washer, Flat 1 11609328 60 Nut, O/Pmp 1 09442946 61 Pin, Oil Press Flf Vlv 1 12551790 62 Screen, O/Pmp (Part of 54) 1 02778192 63 Bolt, Cr/Shf Brg Cap 8 03872781 64 Cap, Cr/Shf Brg 4 03970194 65 Pin, Cr/Shf RR Oil Seal 1 09441003 66 Housing, Cr/Shf RR Oil Seal (Incl 71 & 72) 1 14088556 67 Bolt, Cr/Shf Oil Seal 2 14096659 68 Bolt, Cr/Shf RR Oil Seal Hsg 2 14096658 69 Gasket, Cr/Shf RR Oil Seal Hsg 1 12555771 70 Stud, Cr/Shf Brg Cap 1 03852870 71 Stud, Cr/Shf RR Oil Seal (Part of 66) 2 14080362 72 Seal, Cr/Shf (Part of 66) 1 10088158


297


73 Gear, Flywhl Ring (Part of 78) 1 03991408 74 Washer, Flywhl 1 00136857 75 Bolt, Flywhl (7/16”-20 x 31/32) 6 00839756 76 Bolt, Vlv Push Rod Cvr 4 03814350 77 Bearing, Clu Pilot 1 14061685 78 Flywheel, Eng (Includes 73) 1 93419731 79 Cover 1 93423830 80 Pin, Trans Loc (5/8 x 1 3/16) 2 01453658 81 Gasket, Vlv Push Rod Cvr 1 12378521 82 Plug, Eng Blk Oil Gal 1 14090911 83 Engine Block 1 NSS 84 Plug, CM/Shf 1 110241154 85 Plug, Eng Blk Core Hole AR 03826505 86 Plug, Oil 1 NSS 87 Plug, Eng Blk Oil 1 03835577 88 Tube, Oil Lvl 1 93434708 89 Indicator, Oil Lvl 1 14025224 90 Sealer, Vlv Push Rod Cvr AR 12346286 91 Stud, Vlv Push Rod Cvr 4 00352169 92 Nut, Vlv Push Rod Cvr 4 00451399 93 Washer, Vlv Push Rod Cvr 4 02436163 94 Ring, Cr/Shf Psn Sen Reluctor 1 NSS 95 Seal, Cr/Shf Psn Sen Conn 1 NSS 96 Sensor, Cr/Shf Posn 1 12567712 97 Bolt, Cr/Shf Posn Sen 1 11588712 98 Gasket, F/Pmp 1 93802517 99 Cover, F/Pmp OPG 1 93439184

100 Washer, F/Pmp MT 2 02436162 101 Bolt, F/Pmp 2 09424877 102 Plug, Eng Blk Core Hole 2 88891749


299

Labor Time Guide

300

INTRODUCTION This Guide provides the labor times for repairs and service operations covered under warranty for IMPCO Technologies Engine Systems Divi-sion fuel systems. It applies to 2008 model year 3.0L GM Emission Certified Engines The warranty reimbursement for the labor opera-tions can be calculated when used in conjunction with the IMPCO Policy & Procedures Manual. The labor times published in this Guide identify labor operations and labor times required to per-form a repair, replacement and/or adjustment operation. These times represent those of an av-erage technician in a typical dealership using standard hand tools, equipment and some Spe-cial Service Tools. They are not intended to be used as retail labor rates. LABOR TIME STUDY DEVELOPMENT GENERAL The labor times published in this Guide were de-veloped by IMPCO using genuine IMPCO parts and procedures listed in the IMPCO Service Ma-nual. They include the actual time required to perform the operation and diagnose the system or component failure. All operations also include a standard allowance for “access time” to locate the vehicle, move it to a safe and suitable work area, access the engine, use of Special Service Tools and time to open packaged parts. The times also provide for operation variables but do not include time to remove and/or replace non-IMPCO components and accessories. TOOLS The labor time studies were based on the use of standard hand tools and Special Service Tools. No power-operated tools were used. The labor times were developed by general technicians fol-lowing procedures described in the Service Manual Supplement, Service Publications and good shop practices. The times were calculated using an engine mounted on a stand.

TIME ALLOWANCES The labor times include the removal, disassem-bly, cleaning, re-assembly, installation and/or adjustment of the affected component or assem-bly. Any cleaning time is limited to the installation or replacement of components (such as mating surfaces) and does not include clean-ing other areas of the vehicle contaminated by failure of the component (e.g. coolant sprayed inside the engine compartment). Labor opera-tions that require more than one technician are adjusted to represent the total time for all techni-cians.

GLOSSARY OF TERMS

OPERATION DESCRIPTION The Operation Description identifies the repair to be performed and may include sub-headings such as: ADD conditions, NOTES, INCLUDES and other information. This information is essen-tial for both the technician and warranty claim processing personnel to properly complete a warranty claim for accurate cost recovery. FAILED PART / CAUSAL PART The Failed or Causal Part is the part that caused the repair and/or replacement of other parts. The technician must identify the part as defective (i.e., one that exhibits a flaw or manufacturer’s defect in material or workmanship). The Causal Part must be tagged for warranty failure analy-sis identification prior to returning it to IMPCO Technologies. TROUBLE CODES / CONDITION CODING Each failed or causal part must be coded to iden-tify the manufacturer’s defect of the part as accurately as possible (see Trouble Code chart). The code selected by the repairing technician identifies the manufacturer’s defect and/or work-manship condition qualifying the repair for warranty coverage. ADD CONDITIONS Add Conditions may be required to complete or supplement a labor operation and are included in the Add sections under the Labor Operation De-scription. If an ADD is performed, the allowed

301

labor time for the ADD must be recorded on the shop repair order under the Operation Number. REPLACE Replace is used when the part or assembly is subject to replacement only. This includes the transfer of attached components from the original part to the new part, the installation of the new part and any inspection, adjustment, or required cleaning or lubrication operations. R&R OR REPLACE R&R refers to a part or assembly that is removed and re-installed after the part has been aligned, adjusted, repaired as a separate operation or removed for a sublet repair. Replace means the part or assembly can be replaced with a new (or exchanged) part or assembly (see the Replace paragraph above). INCLUDES

The INCLUDES which follow some of the Labor Descriptions are provided to assist in determining whether or not certain items or functions are in-cluded within the operation (these are not all encompassing to simplify the use of this Guide). Examples include:

Fuel System Evacuation Leak Check Cooling system drain and refill

Refer to the IMPCO Service Manual Supplement or use the Request for Review Form to question and/or recommend changes.

CUSTOMER PROBLEM ANALYSIS

It is the duty of the service technician to translate the customer's complaint into a specific symp-tom. Examples include: stalling, hesitation, surges, engine cranks but will not start, etc. Symptoms also include readily apparent failures to the senses of sight, touch, sound and smell, such as leaking coolant line or cracked casting.

SYMPTOM DIAGNOSIS

Symptom Diagnosis is the process used to de-termine the source of the problem and is the responsibility of both the technician and dealer-ship management. Symptom Diagnosis is

complete when the cause of failure has been identified. REPAIR DIAGNOSIS

These are the checks, tests and measurements required to identify the cause of a failure and/or failed part. Examples include: Cleaning and inspection of all parts. Use of test equipment. Use of common instruments such as an

ohmmeter, volt-amp meter, a leak detector or a cooling system pressure tester that may be required by IMPCO Service Manual Supple-ment procedures.

Repair Diagnosis is the responsibility of the tech-nician. LABOR OPERATION NUMBER

A Labor Operation Number is assigned to the labor performed and must be recorded on the warranty claim. The Labor Operation Number can be found in this Guide or IMPCO Technical Service Bulletins. OVERLAPPING LABOR Overlapping labor is labor time is where two op-erations include the same repair steps. Overlapping time is not compensated; therefore, the repeated labor time must be deducted from the second labor operation so that the total time entered is less than the sum of the combined la-bor times. DUPLICATE LABOR Duplicate Labor is the same labor charged twice, either to two different cost recovery sources, or overlapping labor charged to the same or differ-ent cost recovery sources. Duplicate Labor is not eligible for compensation unless authorized by IMPCO. STRAIGHT TIME

Straight Time is applicable only when a labor op-eration is required and no labor operation description or operation number exists in this Guide. All Straight Time is governed by Policy “A” and is subject to review and approval by IMPCO before payment is reimbursed. Precise

302

labor step documentation indexed to time is re-quired and must be recorded on the shop repair order to identify and justify this expense. Prior approval may be obtained by contacting IMPCO Technical Assistance 1-866-473-2851. ADDITIONAL OR OTHER LABOR Additional or Other Labor may be required when unusual or abnormal conditions are encountered. This time must be identified as such and follow the same time recording and labor step docu-mentation as Straight Time. Warranty compensation for all additional time falls under Policy “A” and is subject to review and approval by IMPCO before payment is reimbursed. Prior approval may be obtained by contacting IMPCO Technical Assistance at 1-866-473-2851. POLICY CODES Certain IMPCO Policy Codes apply to the Gener-ic Labor Operations listed on page 7. Policy codes and descriptions are:

Policy “A” – Is subject to review by IMPCO be-fore reimbursement. Policy “B” – Will require approval from IMPCO before expense is incurred Policy “S” – Sublet of work to a facility outside the normal OEM dealer network, and requires approval from IMPCO prior to incurring the ex-pense All prior approvals may be obtained by contacting IMPCO Technical Assistance at 1-866-473-2851. NORMAL & ADDITIONAL DIAGNOSTICS Normal repair diagnosis time is included in all labor time operations. Additional Diagnostics is

time that is necessary to complete a satisfactory diagnosis that beyond the normal time allowed. This time must be identified as Additional Diag-nostics and follow the same time recording and labor step documentation as Straight Time. It is the responsibility of qualified dealership su-pervisory personnel to assist technicians in both customer Problem Analysis and Symptom Diag-nosis. TECHNICAL ASSISTANCE Service technicians must call the OEM Technical Assistance whenever extensive diagnosis or re-pair advice is required, or to verify a vehicle’s warranty. OEM Technical Assistance personnel must con-tact IMPCO Technical Service personnel to obtain authorization for those repairs or addition-al labor that require prior authorization for warranty compensation. IMPCO Technical As-sistance may be contacted at (1-866-473-2851) between the hours of 8:00 a.m. and 5:00 p.m. Pacific Time Monday through Friday except holi-days. COMPLETED WARRANTY CLAIMS OEMs can choose to submit their electronic forms via an FTP site using the OEM user ID and Passwords (supplied by IMPCO Technical Assis-tance). The forms may be submitted individually or batched. The claims will be reviewed and ap-proved or declined and the OEM will be notified via an electronic response from the IMPCO war-ranty administrator. The OEM may then submit an invoice for payment of approved claims to IMPCO for payment of those claims.

303

FUEL SYSTEM LABOR OPERATIONS

Engine-Electrical

LABOR OPERATION DESCRIPTION OPERATIONNUMBER

TIMEALLOWED

ENGINE CONTROL MODULE (ECM)–REPLACEMENT E0050 0.8

ENGINE CONTROL MODULE (ECM)–REFLASH E0057 0.3

ENGINE WIRE HARNESS–REPAIR E1015 0.9

ENGINE WIRE HARNESS–REPLACEMENT E2015 1.5

PLUGS, SPARK–REPLACE ONE J4226 0.4

PLUGS, SPARK–REPLACE ALL J4227 0.7

WIRES, SPARK PLUG-REPLACE ALL J4207 0.3

COIL, IGNITION–REPLACEMENT J4340 0.6

BRACKET, FUSE BOX-REPLACE E3037 0.4

LPG FUEL CONTROL SYSTEM CHECK INCLUDES: Connect scan tool or test equipment. Check for trouble codes (DTCs), check HEGO operation, disconnect scan tool or test equipment.

M1007 0.3

ELECTRONIC THROTTLE BODY–REPLACEMENT M0075 0.8

THROTTLE BODY/GASKET–REPLACEMENT E3012 0.8

CAP, DISTRIBUTOR - REPLACE J4360 0.2

ROTOR, DISTRIBUTOR - REPLACE J4380 0.2

DISTRIBUTOR ASSEMBLY - REPLACE J4530 0.8

304


Engine-Sensors


TIMEALLOWED

ENGINE OIL PRESSURE SENSOR–REPLACEMENT J4590 0.5

ENGINE COOLANT TEMP SENSOR AND/OR ADAPTER–REPLACE J4591 0.6

CAMSHAFT SENSOR-REPLACEMENT E3019 0.6

CRANK POSITION SENSOR –REPLACEMENT J4592 0.7

TEMP MANIFOLD PRESSURE SENSOR (TMAP)–REPLACEMENT F1015 0.7

FUEL TEMPERATURE/PRESSURE SENSOR–REPLACEMENT E3002 0.5

HEATED EXHAUST GAS OXYGEN SENSOR (HEGO)–REPLACEMENT N1002 0.8

305


Fuel Delivery

LABOR OPERATION DESCRIPTION OPERATION NUMBER

TIME ALLOWED

PRESSURE REGULATOR-REPLACEMENT INCLUDES: Transfer of all fittings

M1001 0.8

PRESSURE REGULATOR REPAIR (SEE M1001 FOR REPLACEMENT) ADD: Allowance for the replacement of regulator port O-rings 0.3

E3005 0.9

0.3

FUEL FILTER, HIGH PRESSURE LIQUID-REPLACE E3041 0.5

FUEL FILTER, LOW PRESSURE VAPOR-REPLACE E3042 0.3

BRACKET, LOW PRESSURE VAPOR LPG FILTER-REPLACE E3052 0.3

BRACKET, REGULATOR MOUNTING–REPLACEMENT E3009 0.5

FUEL INJECTOR, ADAPTER AND/OR FUEL RAIL-REPLACE ADD: Each Additional Fuel Injector ADD: Fuel Injector Hose ADD: Fuel Injector Adapter (each)

E3044

1.0

0.2 0.1 0.1

FUEL RAIL BRACKET-REPLACE E3046 0.3

LEAK CHECK LPG SYSTEM G0004 0.2

LPG FUEL SYSTEM PRESSURE CHECK INCLUDES: Connect fuel pressure gauges. Check regulator primary and secondary pressure. Disconnect gauges.

M1006 0.3

SHUT-OFF VALVE–REPLACEMENT F1003 0.8

306


Exhaust


TIMEALLOWED

CATALYTIC CONVERTER–REPLACEMENT N1001 5.0

RESTRICTED EXHAUST SYSTEM DIAGNOSIS E3017 0.3

Hoses


TIMEALLOWED

COOLANT HOSES–REPLACE ALL INCLUDES: Drain & Fill Radiator

T1001 0.7

COOLANT HOSE PORT FITTING-REPLACE E3047 0.3

FUEL VAPOR HOSE—REPLACE ALL INCLUDES: Replacement of Vapor Hose Port Fittings

E3048 0.4

FUEL VAPOR HOSE PORT-FITTING-REPLACE E3049 0.2

VACUUM LINE-REPLACE ONE ADD: Additional Line Replace Allowances. Diagnosis Time: 0.1

T1002 0.4

0.1

PCV-INSPECT OR REPLACE E3050 0.3

307


Engine-Exterior Components


TIME ALLOWED

WATER PUMP AND/OR GASKET-REPLACE J3480 0.7

STARTER–REPLACEMENT J4560 0.6

ALTERNATOR–REPLACEMENT J4570 0.5

DRIVE BELT–REPLACEMENT J4571 0.5

THERMOSTAT, AND/OR GASKET–REPLACEMENT J4580 0.4

FLYWHEEL/HARMONIC BALANCER–REPLACEMENT J0720 0.5

308


Engine-Manifolds & Cylinder Head Components


TIMEALLOWED

INTAKE MANIFOLD AND/OR GASKET-REPLACEMENT J0210 1.0

EXHAUST MANIFOLD AND/OR GASKET–REPLACEMENT J0108 1.0

VALVE COVER AND/OR GASKET-REPLACEMENT Includes: R&R intake manifold. J0308 0.3

ROCKER ARM–REPLACEMENT Includes: R&R intake manifold and rocker cover(s). ADD: Replace all rocker arms:

J0358

0.4

0.3

STUD, VALVE ROCKER ARM BALL-REPLACEMENT ADD: To replace an additional stud

J0388

0.5 0.3

CYLINDER HEAD GASKET-REPLACEMENT Includes: R&R intake manifold, rocker covers(s) and compression test. J0508 2.3

CYLINDER HEAD-REPLACEMENT Includes: R&R intake manifold, rocker cover(s) and compression test. J0518 3.0

VALVE–RECONDITION OR REPLACEMENT ADD: Each additional cylinder ADD: To recondition all valves ADD: To ream and fit guides for oversize stems

J0528

2.9 0.4 0.9 0.2

VALVE SPRING, CAP AND/OR SEALS–REPLACEMENT Includes: R&R rocker cover(s) ADD: Each additional cylinder ADD: All springs, caps and/or seals

J0548

2.5

0.3 0.9

PUSH ROD–REPLACEMENT, ONE CYLINDER Includes: R&R rocker cover(s) ADD: To replace all push rods:

J0588 0.8

0.2

LIFTER, VALVE–REPLACEMENT, ONE CYLINDER Includes: R&R rocker cover(s) ADD: To replace all lifters:

J0628 0.9

0.3

309


Engine–Internal Components


TIME ALLOWED

TIMING COVER OIL SEAL–REPLACEMENT Includes: R&R balancer J0750 0.7

TIMING COVER AND/OR GASKET–REPLACEMENT Includes: R&R balancer J0780 2.0

TIMING CHAIN–REPLACEMENT ADD: Replace crankshaft gear

J0820 1.6

0.2

CAMSHAFT TIMING GEAR–REPLACEMENT ADD: Replace crankshaft gear

J0840 3.9

0.2

CAMSHAFT–REPLACEMENT J0850 6.0

OIL PAN AND/OR GASKET–REPLACEMENT Includes: Fluid replacement J1000 2.2

PUMP, ENGINE OIL–REPLACEMENT Includes: R&R engine oil pan and fluid replacement J1020 2.5

SEAL, REAR MAIN BEARING–REPLACEMENT Includes: R&R engine oil pan and fluid, replace lower seal and repack upper seal

J1120 2.8

BEARING, CRANKSHAFT MAIN–REPLACE ONE Includes: R&R engine oil pan and fluid, and use of plastic type gauge ADD: Replace main bearings Each additional (NOT to equal or exceed ALL) All main bearings ADD: Replace connecting rod bearings

Each additional (NOT to equal or exceed ALL) All rod bearings

J1200

4.1

0.5 1.2

0.3 1.2

310


Engine–Internal Components


TIME ALLOWED

BEARING, CONNECTING ROD–REPLACE ONE Includes: R&R engine oil pan and fluid, and use of plastic type gauge ADD: Replace connecting rod bearings

Each additional (NOT to equal or exceed ALL) All rod bearings

J1180

2.9

0.4 2.0

PISTON, ROD AND/OR RINGS–REPLACEMENT Includes: R&R all necessary components and use of plastic type gauge ADD: Replace rings only Each piston (NOT to exceed ALL) All pistons ADD: To replace connecting rods only Each rod (NOT to exceed ALL) All rods ADD: To replace pistons only Each piston (NOT to exceed ALL) All pistons

J1308

3.3

0.4 2.2

0.3 1.2

0.4 2.4

PLUG, EXPANSION–REPLACEMENT Note: Use appropriate labor operation(s) for removal of necessary component(s) to gain access to plug

J1600 0.3

PLUG, OIL GALLERY–REPLACEMENT Note: Use appropriate labor operation(s) for removal of necessary component(s)

J1640 0.3

311

ENGINE REPAIR OPERATIONS

Engine–Replacement


TIME ALLOWED

BLOCK, ENGINE FITTED–REPLACEMENT Includes: R& R all components, fluids and accessories ADD: To recondition all valves and guides

J1800 9.0

2.6

ENGINE, PARTIAL–REPLACEMENT Includes: R& R all components, fluids and accessories ADD: To recondition all valves and guides

J1820 7.2

2.6

ENGINE, ASSEMBLY–REPLACEMENT Includes: R&R all components, fluids and accessories J1880 3.5

ENGINE, MOUNTS, FRONT–REPLACEMENT J1506 0.3

312

MISCELLANEOUS


TIMEALLOWED

ADDITIONAL DIAGNOSTIC TIME Policy “B” Subject to review by IMPCO Technical Support

G0001 Policy “B” 0.5

FASTENER OR FITTING TIGHTENING G0003 0.1

DRIVE TESTS G0006 0.2

SUBLET TIME Policy “S”* *Requires Prior Approval By IMPCO Technical Support;

G0007 Policy “S” 0.0

313

REQUEST FOR REVIEW OF LABOR TIMES

IMPCO will provide all possible assistance in the development process, the content of individual stan-dards, the means for accomplishing repairs within the times established and the assurance that every effort has been made to maintain the accuracy of these times. IMPCO will review and, if necessary, ad-just any allowance that is inconsistent with the time actually being spent on warranty repairs that are within the scope and definitions described in this guide. Although the same methods of labor time allowance development are applied to every labor time study, the actual time required to make a repair on a like component may vary. Changes to labor times are made based on one or more of the following:

Design change of the component.

Design change in other components that affect the accessibility to the repaired component.

Change in the procedure or method of repair.

Change in the tools or equipment used to make the repair.

Final review and verification of times after receiving a Request for Review form. Questions and/or suggestions regarding labor operations or time allowances in the Labor Time Guide must be submitted on a Request for Review form. This form is the last page of this guide. A properly completed form will provide IMPCO detailed information identifying the technician’s difficulties in performing a labor operation within the published labor time allowance. When completing this form, it is important that all vehicle identification data affecting or influencing the operation in question be pro-vided. OEM RESPONSIBILITIES

Your request for review must include a detailed, step by step description of your labor procedure in the space provided. This will allow IMPCO to both understand your concern and potential cause(s) for the variance between your actual time and the published labor time.

When submitting a Request for Review, the following steps are required:

Verify that the technician has followed Service Manual Supplement procedure and utilized all neces-sary equipment and is properly trained.

Complete the Request for Review Form included in this Guide.

Use one form for each labor allowance in question (or combination of standards representing one re-pair job).

Provide specific performance time for two repairs performed by the same technician to assist in de-termining average time.

Identify the technician involved, should it be necessary to review the process.

Provide comments that may help in identifying the problem area including individual step times.

Sign and forward the form to IMPCO.

IMPCO RESPONSIBILITIES

Upon receipt of the Request for Review form, IMPCO will review the procedure and consider changing the labor time. Changes in a labor time will appear as a Warranty Bulletin or the next revision of the La-bor Time Guide.

314

COMPLETING THE REQUEST FOR REVIEW FORM

When completing the request for review form, include a detailed description of each step, list all compo-nents, numbers, type of fasteners, and any Special Service Tools or procedures that are required. Use the Labor Time Study form and include it with the Request for Review sheet on page 18. When complete, send both forms to: IMPCO Technologies 3030 South Susan Street Santa Ana, CA. 92704 Attn: Technical Service Labor Time Review

315

REQUEST FOR REVIEW

Please insure this Request for Review is filled out completely so that it can be investigated and processed without delay.

SERVICE FACILITY INFORMATION

Service Facility Name:

Service Facility Address:

City: State: Zip Code

Telephone Number ( ) Fax Number: ( )

OPERATION NUMBER CURRENT PUBLISHED

TIME SUGGESTED TIME

VEHICLE INFORMATION:

Model Year Model Line SERIAL#

Mileage _____________________ Engine _______________________

TECHNICIAN INFORMATION:

Technician’s Name

Are you certified in this area of repair? Yes No

How many times have you performed this repair? Once Twice How many?

Is the IMPCO Service Manual Supplement accurate? Yes No Describe the inaccuracy:

(Please include any additional inaccuracies and/or suggestions on a separate sheet. We welcome your input.)

Have you attended an IMPCO Technical Training Class for this type of work? Yes No

SERVICE MANAGER SIGNATURE: (required)

Date: (required) _____________________

A detailed, step by step labor description is required on the back of this form before a labor time study will be considered for review.

316

LABOR TIME STUDY FORM

Step Labor Description Watch Time (Min/Sec)

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

(Attach additional sheets if necessary)

Total Repair Time (minutes/seconds)

317

Definitions

318

Air Valve Vacuum (AVV): The vacuum signal tak-en from below the air valve assembly and above the throttle butterfly valve.

ADP: Adaptive Digital Processor. Air/Fuel Ratio: The amount or balance of air and

fuel in the air fuel mixture that enters the engine. Analog Voltmeter: A meter that uses a mechani-

cal needle to point to a value on a scale of numbers. It is usually of the low impedance type and used to measure voltage and resistance.

Aromatics: Pertaining to or containing the six-carbon ring characteristic of the benzene series. Found in many petroleum distillates.

Backfire: Combustion of the air/fuel mixture in the intake or exhaust manifolds. A backfire can occur if the intake or exhaust valves are open when there is a mis-timed ignition spark.

Benzene: An aromatic (C6H6). Sometimes blended with gasoline to improve anti-knock value. Ben-zene is toxic and suspected of causing cancer.

Bi-Fueled: A vehicle equipped to run on two fuels. Blow-By: Gases formed by the combustion of fuel

and air, which ordinarily should exert pressure only against the piston crown and first compres-sion ring. When rings do not seal, these gases escape or “blow by” the side of the piston into the crankcase.

BTU: British Thermal Unit. A measurement of the amount of heat required to raise the temperature of 1lb. of water 1 degree F.

Butane: An odorless, colorless gas, C4H10 found in natural gas and petroleum. One of the five LP gases.

CAFE: Corporate Average Fuel Economy. CARB: California Air Resources Board. Carbon Monoxide (CO): A chemical compound of

a highly toxic gas that is both odorless and color-less.

Carburetor: An apparatus for supplying an inter-nal-combustion engine a mixture of vaporized fuel and air.

Cathode Ray Tube: A vacuum tube in which ca-thode rays usually in the form of a slender beam are projected on a fluorescent screen and pro-duce a luminous spot.

Circuit: A path of conductors through which elec-tricity flows.

Closed Loop Operation: Applies to systems utiliz-ing an oxygen sensor. In this mode of operation, the system uses oxygen sensor information to de-termine air/fuel ratio. Adjustments are made accordingly and checked by comparing the new oxygen sensor to previous signals. No stored in-formation is used.

CNG: Compressed Natural Gas. CKP: Crankshaft Position Sensor CMP: Camshaft Position Sensor Conductor: A material, normally metallic, that

permits easy passage of electricity. Contaminants: Impurities or foreign material

present in fuel. Control Module: One of several informal names

for a solid state microcomputer which monitors engine conditions and controls certain engine functions; i.e. air/fuel ratio, injection and ignition time, etc. The formal name and the one used throughout this manual is ECM, or Engine Control Module.

Converter: A LPG fuel system component contain-ing varying stages of fuel pressure regulation combined with a vaporizer.

Cryogen: A refrigerant used to obtain very low temperatures.

Current: The volume or flow of electrons through a conductor. Measured in amperes or amps.

DBW: Drive By Wire Dedicated Fuel System: A motor fuel system de-

signed to operate on only one fuel type. Diaphragm: A thin, flexible membrane that sepa-

rates two chambers. When the pressure in one chamber is lower than in the other chamber, the diaphragm will move toward the side with the low pressure.

Diaphragm Port: The external port located at the fuel inlet assembly and connected to the vacuum chamber above the air valve diaphragm.

DLC: Data Link Connector. DTC: Diagnostic Trouble Code DST: Diagnostic Scan Tool. DVOM: Digital Volt/ohm Meter. A meter that uses a

numerical display in place of a gauge and is usually of the high impedance type.

ECT: Engine Coolant Temperature. ECM: Electronic Control Module ECOM: A DLC cable supporting CAN and serial

communication with a Spectrum II or III ECM. EFI: Electronic Fuel Injection. A fuel injection sys-

tem, which uses a microcomputer (ECM) to determine and control the amount of fuel, re-quired by, and injected into, a particular engine.

EGO: Exhaust Gas Oxygen, used to describe a sensor. Also known as “HEGO” (Heat Exhaust Gas Oxygen) sensor, “O2” or “Oxygen sensor.

EGR: Exhaust Gas Recirculation. EPA: Environmental Protection Agency: A regulat-

ing agency of the Federal government which, among other duties, establishes and enforces au-tomotive emissions standards.

319

Ethanol: Grain alcohol (C2H5OH), generally pro-duced by fermenting starch or sugar.

Evaporative Emissions Controls: An automotive emission control system designed to reduce hy-drocarbon emissions by trapping evaporated fuel vapors from the fuel system.

Excess Flow Valve: A check valve that is caused to close by the fuel when the flow exceeds a pre-determined rate.

FTV: Fuel Trim Valve. FFV: Flexible Fuel Vehicle. Firing Line: The portion of an oscilloscope pattern

that represents the total amount of voltage being expended through the secondary circuit.

FMVSS: Federal Motor Vehicle Safety Standards. FPP: Foot Pedal Position Sensor Fuel Injector: a spring loaded, electromagnetic

valve which delivers fuel into the intake manifold, in response to an electrical input from the control module.

Fuel Lock: A solenoid-controlled valve located in the fuel line to stop the flow when the engine stops or the ignition switch is off.

Gasohol: 10 percent ethanol, 90 percent gasoline. Often referred to as E-10.

Gasoline: A motor vehicle fuel that is a complex blend of hydrocarbons and additives. Typical oc-tane level is 89.

GCP: Spectrum III (90-pin) ECM. Greenhouse Effect: A scientific theory suggesting

that carbon dioxide from the burning of fossil fuels is causing the atmosphere to trap heat and cause global warming.

HC: Hydrocarbon. An organic chemical compound. HD 10: A fuel of not less than 80% liquid volume

propane and not more than 10% liquid volume propylene.

HD 5: A fuel of not less than 90% liquid volume propane and not more than 5% liquid volume propylene.

HDV: Heavy Duty Vehicle. Heavy Ends: A term used to describe the buildup

of wax-like impurities that fall out of LPG when vaporized.

HEGO: Heated Exhaust Gas Oxygen, used to de-scribe a sensor. Also known as “EGO” (Exhaust Gas Oxygen sensor), “O2” or “Oxygen sensor.

Hg: Chemical symbol for the element mercury. Used in reference to a measure of vacuum (inch-es of Hg).

Histogram: The graphical version of a table which shows what proportion of values fall into specific categories over a specific period of time.

Hydrocarbon: A chemical compound made up of hydrogen and carbon (HC). Gasoline and almost all other fuels are hydrocarbons.

Hydrostatic Relief Valve: A pressure relief device installed in the liquid LPG hose on a LPG fuel system.

IAT: Intake Air Temperature Ideal Mixture: The air/fuel ratio at which the best

compromise of engine performance to exhaust emissions is obtained. Typically 14.7:1.

Ignition Reserve: The difference between availa-ble voltage and the required voltage.

ILEV: Inherently Low Emission Vehicle. IMPCO: Imperial Machine Products Company. IMPCO Technologies, Inc. A manufacturer of both

LPG and Gasoline fuel systems. Impedance: A form of opposition of AC electrical

current flow (resistance) measured in ohms. Insulation: A nonconductive material used to cover

wires in electrical circuits to prevent the leakage of electricity and to protect the wire from corro-sion.

Intercept: An electrical term for a type of splice where the original circuit is interrupted and redi-rected through another circuit.

ITK: IMPCO Test Kit Knock: Sound produced when an engine’s air/fuel

mixture is ignited by something other than the spark plug, such as a hot spot in the combustion chamber. Also caused by a fuel with an octane rating that is too low and/or incorrect ignition tim-ing. Also called detonation or ping.

Lambda Sensor: A feedback device, usually lo-cated in the exhaust manifold, which detects the amount of oxygen present in exhaust gases in re-lation to the surrounding atmosphere. (See HEGO).

LDV: Light Duty Vehicle. Lean Mixture: An air to fuel ratio above the stoi-

chiometric ratio; too much air. LEV: Low Emission Vehicle. Limp-in or Limp Home: A mode where the ECM

or a component has failed, but the vehicle re-mains operational although the engine may operate minimally. This term may also describe the drivability characteristics of a failed computer system.

Liquid Petroleum Gas (LPG): A fuel commonly known as propane consisting mostly of propane (C3H8), derived from the liquid components of natural gas stripped out before the gas enters the pipeline, and the lightest hydrocarbons produced during petroleum refining. Octane level of LPG is 107.

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LPG: Liquified Petroleum Gas. M85: A blend of gasoline and methanol consisting

of 85% methanol and 15% gasoline. Measurements of Pressure: 1 PSI=2.06” Hg

(mercury) = 27.72” H2O (water column). At sea level atmospheric pressure is 29.92” Hg.

Methanol: Known as wood alcohol (CH3OH), a light, volatile, flammable alcohol commonly made from natural gas.

MIL: Malfunction Indicator Lamp. Misfire: Failure of the air/fuel mixture to ignite dur-

ing the power stroke. Mixer: Fuel introduction device that does not in-

clude a throttle plate. MFI: Multiport Fuel Injection. A fuel injection system

that uses one injector per cylinder mounted on the engine to spray fuel near the intake valve area of combustion chamber.

MSV: Manual Shut-Off Valve. Refers to the ma-nually operated valve on the LPG tank.

MTBE: Methyl Tertiary Butyl Ether. Oxygenate add to gasoline to reduce harmful emissions and to improve the octane rating.

Multi-fuel System: A motor fuel system designed to operate on two different fuels, such as LPG and gasoline.

Natural Gas: A gas formed naturally from buried organic material, composed of a mixture of hy-drocarbons, with methane (CH4) being the dominant component.

NGV: Natural Gas Vehicle. NOX: See Oxides of Nitrogen. OBD: On Board Diagnostic Octane Rating: The measurement of the antiknock

value of a motor fuel. OEM: Original Equipment Manufacturer, the vehicle

manufacturer. Open-Loop: An operational mode during which

control module memory information is used to de-termine air/fuel ratio, injection timing, etc., as opposed to actual oxygen sensor input.

Orifice: A port or passage with a calibrated open-ing designed to control or limit the amount of flow through it.

Oscilloscope: An instrument that converts voltage and frequency readings into traces on a cathode ray tube (also see Cathode Ray Tube).

Oxides of Nitrogen: Chemical compounds of ni-trogen bonded to various amounts of oxygen (NOX). A chief smog forming-agent.

Oxygen Sensor: An automotive fuel system that produces a signal in accordance with the oxygen content of the exhaust gas. (See Lambda Sen-sor).

Oxygenate: Oxygenates (such as MTBE, ethanol and methanol) added to gasoline to increase the oxygen content and therefore reduce exhaust emissions.

Ozone: A radical oxygen module (O3) that is found in the upper atmosphere and filters out ultraviolet radiation from the sun. Ground level ozone is formed by NOX, during the formation of photo-chemical smog.

Particulates: Microscopic pieces of solid or liquid substances such as lead and carbon that are dis-charged into the atmosphere by internal combustion engines.

Positive Crankcase Ventilation (PCV): An auto-motive emission control system designed to reduce hydrocarbon emissions by routing crank-case fumes into the intake manifold rather than to the atmosphere.

Power Derate: A mode of reduced engine power output for the purposes of protecting engine com-ponents during a failure or malfunction.

Pressure Differential: The differential between atmospheric pressure and intake manifold (re-ferred to as vacuum) pressure.

Pressure Regulator: A device to control the pres-sure of fuel delivered to the fuel injector(s).

Primary Circuit: The low-voltage or input side of the ignition coil.

Propane: An odorless and colorless gas, C3H8, found in natural gas and petroleum.

Psia: pounds per square inch absolute PTV: Pressure Trim Valve Reactivity: Refers to the tendency of an HC in the

presence of NOX and sunlight to cause a smog-forming reaction. The lighter the HC, the lower reactivity tends to be.

Regulator: An assembly used to reduce and con-trol the pressure of a liquid or vapor.

Resistance: The opposition to the flow of current in an electrical circuit. Measured in ohms.

Rest Pressure: Fuel pressure maintained within the system after engine shutdown.

Rich Mixture: An air to fuel ratio below the stoichi-ometric ratio; too much fuel.

SAE: Society of Automotive Engineers. Secondary Circuit: The high-voltage output side of

the ignition coil. SEFI or SFI: Sequential Electronic Fuel Injection or

Sequential Fuel Injection. Sensors: Devices that provide the control module

with engine information as needed to properly control engine function.

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Spark Line: The portion of an oscilloscope pattern that represents the time during which the air/fuel mixture is being burned in the combustion cham-ber.

Splice: An electrical term for the joining of two or more conductors at a single point.

Stoichiometric Ratio: An ideal fuel/air ratio for combustion in which all of the fuel and most of the oxygen will be burned.

Sulfur Oxides: Chemical compounds where sulfur is bonded to oxygen produced by the combustion of gasoline or any other fuel that contains sulfur. As sulfur oxides combine with water in the at-mosphere to form sulfuric acid.

System Pressure: The fuel pressure maintained in the system during normal engine operation.

Tap: An electrical term for a type of splice where the original circuit is not interrupted.

TBI: Throttle Body Injection. Any of several injec-tion systems that have the fuel injector(s) mounted in a centrally located throttle body.

Throttle Body: Controls engine RPM by adjusting the engine manifold vacuum to the mixer. Con-sists of a housing shaft, throttle liner and butterfly valve.

TLEV: Transitional Low Emission Vehicle. TMAP: Combined Air Inlet and Manifold Pressure

Sensor. Toluene: A liquid aromatic hydrocarbon C7H8. TPS: Throttle Position Sensor.

TSB: Technical Service Bulletin. ULEV: Ultra Low Emission Vehicle. USB: Universal Serial Bus. A plug or interface sup-

plied on most personal computers. Vaporization: A process in which liquid changes

states into gas. Venturi Air Valve Vacuum (VAVV): An amplified

air valve vacuum signal coming from the venturi area of the mixer, directly exposed to airflow be-fore the addition of vaporized LPG.

Volt/ohmmeter (VOM): A combination meter used to measure voltage and resistance in an electrical circuit. Available in both analog and digital types. May also referred to as AVOM and DVOM.

Voltage: The electrical pressure that causes cur-rent to flow in a circuit. Measured in volts.

Voltage Drop: A lowering of the voltage in a circuit when resistance or electrical load is added.

Voltmeter: A meter that uses a needle to point to a value on a scale of numbers usually of the low impedance type; used to measure voltage and resistance.

VSS: Vehicle Speed Sensor Xylene: C6H4 (CH3)2. Any of three toxic, flammable,

and oily isomeric aromatic hydrocarbons that are dimethyl homologues of benzene and usually ob-tained from petroleum or natural gas distillates.

ZEV: Zero Emission Vehicle.

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Appendix

324

Altitude vs. Barometric Pressure

Altitude Measured In Feet (ft)

Kilopascals (kpa)

Pounds Per Square Inch (PSIA)

14,000 56-64 8.1-9.2

13,000 58-66 8.4-9.6

12,000 61-69 8.8-10.0

11,000 64-72 9.3-10.4

10,000 66-74 9.6-10.7

9,000 69-77 10.0-11.2

8,000 71-79 10.3-11.4

7,000 74-82 10.7-11.9

6,000 77-85 11.2-12.3

5,000 80-88 11.6-12.8

4,000 83-91 12.0-13.2

3,000 87-95 12.6-13.8

2,000 90-98 13.0-14.2

1,000 94-102 13.6-14.8

0 96-104 13.9-15.0

-1,000 101-105 14.6-15.2

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Ignition System Specifications

Firing Order 1-6-5-4-3-2

Spark Plug Type R44LTS (AC Plug)

Spark Plug Gap .035 in (0.889 mm)

Spark Plug Torque 11 lb ft (15 N·m)

Spark Plug Wire Resistance 1000 Ohms per ft.

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Extended ECT Temperature vs. Resistance

Degrees F. Degrees C. Ohms±10%

302 150 47

284 140 60

266 130 77

248 120 100

230 110 132

212 100 177

194 90 241

176 80 332

158 70 467

140 60 667

122 50 973

113 45 1188

104 40 1459

95 35 1802

86 30 2238

77 25 2796

68 20 3520

59 15 4450

50 10 5670

41 5 7280

32 0 9420

23 -5 12300

14 -10 16180

5 -15 21450

-4 -20 28680

-22 -30 52700

-40 -40 100700

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DTC (SPN & FMI Chart)

2011 emission certified lpg fuel system 3.0l gm enginelpg is stored in the fuel tank as a liq-uid....

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