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Campaign - PCM Reprogramming: Overview

98066 - Special Policy Adjustment - Linear Exhaust Gas Recirculation System # 98066

Table 1: 1995 4.3 L (L35) LEGR Valve Only

Table 2: 1995 4.3 L (L35) MEMCAL Only (PCM Applications)

Table 3: 1995 4.3 L (L35) FLASH Calibrations Only (VCMX-A Applications)

98066 -- SPECIAL POLICY ADJUSTMENT -- LINEAR EXHAUST GAS RECIRCULATION SYSTEM

1995 S/T, M/L TRUCKS

EQUIPPED WITH 4.3 L ENGINE (RPO L35 -- VIN CODE W)

Condition

Some customers of 1995 model year S/T and M/L trucks equipped with 4.3 L engine (RPO L35 and VIN Code W) may experience Linear EGR valve sticking, or foreign material holding the valve open/closed. This will cause a DTC 32 (in vehicles equipped with PCM controllers) or DTC 1406 (in vehicles equipped with VCMX-A controllers) to be set which may be accompanied by poor driveability conditions such as engine surge, engine knock, engine stall, rough idle, and/or hard starting.

Cause

Carbon deposits or foreign material may be affecting Linear EGR valve operation.

Special Policy Adjustment

This special policy covers the condition described above for a period of seven (7) years or 75,000 miles (120,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership.

The repairs will be made at no charge to the owner, This special policy applies ONLY to repairs requiring Linear EGR system servicing. The customer should not be charged for performing a system check when determining that the LEGR system is not involved with a customer complaint (labor operation T5517 is provided to submit claims for such system checks). Any additional necessary diagnosis and repairs that are not related to the LEGR condition are NOT covered by this special policy. The customer should be informed that any further service that is not covered by new vehicle warranty will not be covered by this policy.

Vehicles Involved





Involved are all 1995 S/T and M/L model vehicles equipped with 4.3 L engines (RPO L35 and VIN Code W) and built within the VIN breakpoints as shown.

Parts Information





Parts required to complete this Special Policy are to be obtained from General Motors Service Parts Operations (GMSPO). Normal orders should be placed on a DRO = Daily Replenishment Order. In an emergency situation, parts should be ordered on a CSO = Customer Special Order.





The table shows the S/T flash calibration and Techline CD number. Do not order these flash calibrations from GMSPO.

Customer Notification

Customers will be notified of this Special Policy on their vehicles by General Motors (see copy of typical customer letter as shown in this bulletin -- actual divisional letter may vary slightly).

Customer Reimbursement

Customer claims for reimbursement on previously paid repairs to service the LEGR system are to be submitted by February 15, 2000 (this time limitation may be longer depending on the law in some states, such as California, Connecticut, Virginia, and Wisconsin). Repairs must have occurred within seven years of the date the vehicle was originally placed in service, or 75,000 miles (120,000 km), whichever occurs first. Owners (and/or prior owners) must submit original documentation which reasonably confirms the amount of the unreimbursed repair expense(s), a description of the repair, date of the repair, and the person or entity performing the repair. CUSTOMERS FROM THE STATES OF CALIFORNIA, CONNECTICUT, VIRGINIA, AND WISCONSIN MUST SUBMIT REQUESTS FOR REIMBURSEMENT DIRECTLY TO CHEVROLET OR PONTIAC-GMC PER INSTRUCTIONS IN THE OWNER LETTER.

Service Procedure

System Check

Check for Diagnostic Test Code (DTC) 32 (vehicles equipped with Powertrain Control Module) or DTC 1406 (vehicles equipped with Vehicle Control Module) with Tech I or Tech II. If DTC 32 or 1406 is not present, perform LEGR Debris Purge and Function Test (listed below) to verify normal operation of the LEGR Valve. If the LEGR system is operating properly, inform the customer that their vehicle does not have the condition listed in the owner letter. If poor driveability conditions persist, inform the customer that any further diagnosis and repairs will be at their expense if vehicle is outside the parameters of the new vehicle warranty.

Correction

If DTC is present, install new Memcal from the PARTS INFORMATION tables listed in this bulletin (for vehicle equipped with PCM) or reflash the engine calibration from the latest Techline CD (for vehicle equipped with VCM). After installing the new Memcal or reflashing, perform the LEGR Debris Purge and Function Check listed below.

LEGR Debris Purge and Function Check

Using a Tech I or Tech II, with transmission in park, parking brake applied, and engine at 1,500 RPM, command the LEGR valve to 100% position. Then command the LEGR valve to 0% position while monitoring actual and desired LEGR position. This procedure is intended to clear any foreign material from the valve.

Did the LEGR valve desired position agree with the actual position? If yes, the LEGR valve is functioning normally. If not, repeat the debris purge test. If the desired and actual valve positions still do not agree, refer to DTC 32 or 1406 section of the Driveablity and Emissions manual.

Vehicle (LEGR) Road Test

If the engine is operating normally after the Memcal replacement and/or LEGR valve replacement (if necessary after referring to DTC 32 or 1406 section of the Driveability and Emissions manual), a road test should be performed. During vehicle road test, after installing the new Memcal, the technician may notice increased LEGR valve activity during light throttle maneuvers. This increased activity is due to the LEGR valve stroking during which time the actual position will momentarily exceed the desired position. This is normal LEGR function with this calibration. Road test the vehicle for reported driveability concerns and verify LEGR function. Have any noted problems been corrected? If yes. system is OK: return vehicle to customer. If not, refer to appropriate section of the Driveability and Emissions manual.

Claim Information








Submit a claim with the information as shown.

Reimbursement

Customer requests for reimbursement of previously paid repairs to correct Linear Exhaust Gas Recirculation system are to be submitted prior to or by February 15, 2000 (this time limitation may be longer depending upon the law in your state)

When a customer requests reimbursement, they must provide the following:

^ Proof of ownership at time of repair.

^ Original paid receipt confirming the amount of unreimbursed repair expense(s) a description of the repair, and the person or entity performing the repair.

Claims for customer reimbursement on previously paid repairs are to be submitted as required by WINS

Notice
Refer to the appropriate divisional service policies and procedures manual, section 1.6.1, for specific procedures regarding customer reimbursement verification.





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