CAMPAIGN: ENHANCE MEMCAL 1993 C/K TRUCKS

SUBJECT: ENHANCED MEM-CAL

MODELS: 1993 C/K TRUCK WITH 5.0L ENGINE (L03) AND 4-SPEED AUTOMATIC TRANSMISSION (M30)

General Motors has installed an enhanced memory calibration in 1993 GMC Trucks equipped with 5.0L engines (L03) and 4-speed automatic transmissions (M30) built after July 17, 1992. Dealers are to install the enhanced Mem-Cal that has been provided according to the vehicle type, axle ratio and location (California/Federal) prior to delivery. If a vehicle has been sold, contact the owner to make this correction.

VEHICLES INVOLVED

Involved are certain 1993 C/K trucks. Dealer codes and vehicles involved are listed below: NEW OLD MEM-CAL MEM-CAL DEALER CODE VEHICLE IDENTIFICATION CODE CODE

48-42078 2GTEC19H2P1500008 BDFS BBLS 48-47308 2GTEC19H1P1500081 BDFL BBLL 48-42244 2GTEC19H6P1500089 BDFT BBLT 48-51218 2GTEC19H9P1500104 BDFK BBLK 48-42238 2GTEC19H1P1500209 BDFT BBLT 48-06151 2GTEK19H6P1500257 BDFL BBLL 48-42238 2GTEC19H8P1500272 BDFT BBLT 48-21703 2GTEC19H2P1500316 BDFL BBLL 48-42298 2GTEC19H0P1500332 BDFT BBLT

48-42023 2GTEC19H4P1500334 BDFT BBLT 48-42308 2GTEC19H3P1500342 BDFT BBLT 48-42102 2GTEC19H4P1500351 BDFT BBLT 48-42023 2GTEC19H2P1500364 BDFT BBLT 48-42102 2GTEC19H1P1500369 BDFT BBLT 48-06440 2GTEK19H5P1500412 BDFL BBLL 48-42023 2GTEC19H0P1500413 BDFT BBLT 48-51038 2GTEC19H9P1500426 BDFK BBLK 48-42308 2GTEC19H8P1500451 BDFT BBLT 48-51304 2GTEC19H3P1500535 BDFK BBLK 48-47338 2GTEC19H3P1500633 BDFL BBLL 48-47590 2GTEC19H9P1500653 BDFL BBLL 48-21127 2GTEC19H4P1500656 BDFL BBLL 48-51304 2GTEC19HXP1500693 BDFK BBLK 48-51018 2GTEC19H9P1500734 BDFL BBLL 48-51219 2GTEC19H3P1500745 BDFK BBLK 48-51007 2GTEC19H1P1500775 BDFL BBLL 48-42244 2GTEC19H7P1500795 BDFT BBLT 48-51018 2GTEC19H8P1500837 BDFL BBLL 48-26507 2GTEC19H3P1500874 BDFL BBLL 48-47308 2GTEC19H3P1500888 BDFL BBLL 48-47308 2GTEC19H2P1500896 BDFL BBLL 48-44041 2GTEC19HXP1501004 BDFL BBLL 48-10500 2GTEC19H7P1501011 BDFL BBLL 48-21127 2GTEC19HBP1501082 BDFL BBLL 48-51219 2GTEC19H1P1501098 BDFK BBLK

DEALER CAMPAIGN RESPONSIBILITY

Dealers are to correct all affected vehicles in new vehicle stock prior to their sale. Should vehicles be sold inadvertently from your new vehicle inventory, prior to repair, owners are to be contacted by the dealer and arrangements made to make the required correction according to instructions contained in this campaign message.

Dealers are to service all vehicles subject to this campaign, at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time forward.

OWNER NOTIFICATION

There will be no owner letter sent out with this campaign. It is anticipated the vehicles should still be in your new vehicle inventory and should be repaired prior to retail sale. If a unit has been retailed or dealer transferred, please contact the respective purchaser or dealer to have the campaign repair performed.

SERVICE INFORMATION

1. Disconnect negative battery cable.

2. Disconnect connectors from ECM/PCM.

3. Remove ECM/PCM mounting hardware.

4. Remove ECM/PCM from passenger compartment.

5. Remove ECM/PCM access cover.

6. Remove Mem-Cal. IMPORTANT: Using two fingers, push both retaining clips back away from the Mem-Cal. At the same time, grasp it at both ends and lift it up out of the socket. Use of unapproved Mem-Cal removal methods may cause damage to the ECM/PCM socket.

7. Install new Mem-Cal. IMPORTANT: Press only on the ends of the Mem-Cal. Small notches in the Mem-Cal must be aligned with the small notches in the Mem-Cal socket. Gently press down on the ends of the Mem-Cal until clips are against the side of the Mem-Cal. Press inward on the clips until they snap into place. Listen for the click.

8. Install access cover on ECM/PCM.

9. Connect connectors to ECM/PCM.

10. Make functional check

A. Turn ignition on.

B. With cavities A & B shorted at ALDL connector, code 12 should flash four times (if no other codes are present). This indicates the Mem-Cal is installed properly, and the ECM/PCM functioning.

11. Install ECM/PCM in vehicle using mounting hardware removed in Step 3 (1.6 - 2.2 Nm).

12. Connect negative battery cable (10.2 - 20.0 Nm).

13. Install Campaign Identification Label.

PARTS INFORMATION

Parts required to complete this campaign are being shipped direct to involved dealers by GMC Truck on a no charge basis. Parts are expected to be shipped August 14, 1992 via overnight mail. The correct Mem-Cal for each application is identified by a four letter broadcast code as listed in the "Vehicles Involved" section of this message.

WARRANTY INFORMATION

Dealers should submit an accurately filled out Warranty Repair Order on each vehicle completed under this campaign.

LABOR OPERATION *TIME **PARTS TROUBLE NUMBER DESCRIPTION ALLOWANCE ALLOWANCE CODE -------- --------------- ----------- --------- ------ V7660 Replace Mem-Cal 0.3 Hrs. $6.90 96

* For dealer to receive Administrative Time Allowance associated with this campaign, add 0.1 hour to the Labor Operation Time Allowance.

** The $6.90 identified in the "Parts Allowance" column represents 30% of dealer net for Mem-Cal shipped direct to dealers by GMC Truck Division.

CAMPAIGN IDENTIFICATION LABEL

Each vehicle corrected in accordance with the instructions outlined in this campaign will require a "Campaign Identification Label". Each label provides a space to include the Campaign Number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or ball point pen.

Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in for periodic servicing by the owner.

Apply "Campaign Identification Label" only on a clean, dry surface.

ADMINISTRATIVE PROCEDURE

Procedures covering this campaign are outlined in Section V of your dealership's "GM Truck Claims Processing Manual" #P9119.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.