CAMPAIGN: LOW VACUUM BRAKE MODULE NOT INSTALLED

1985 NINETY-EIGHTS WITH 4.3L DIESEL ENGINE (VIN CODE T)

CONDITION

General Motors has determined that some 1985 Ninety-Eight models equipped with diesel engines may have been assembled without the low vacuum brake module. Without this module, the "Brake" warning light located on the instrument panel would not be turned on if the vacuum in the brake booster should go to a low level.

VEHICLES INVOLVED

Certain 1985 Ninety-Eight models equipped with 4.3L diesel engines (VIN Code T) within the following serial numbers:

Assembly Plant Beginning Up to and Including -------------- --------- -------------------

Wentzville (1) F1327659 F1351213

DEALER ACTION

To correct this condition, dealers are to check and determine if the module was installed on vehicles involved and, if required, install the module. Dealers are to service all vehicles subject to this campaign at no charge to the owner, regardless of mileage, age of vehicle, or ownership, from this time forward.

Whenever a vehicle subject to this campaign is taken into your new or used vehicle inventory, or is in your dealership for service in the future, you should take the steps necessary to be sure the campaign correction has been made before reselling or releasing the vehicle. Owners of vehicles recently sold from your new vehicle inventory are to be contacted by the dealer, and arrangements made to make the required modification according to instructions contained in this bulletin.

SERVICE PROCEDURE

A. Inspection ----------

1. With ignition "Off", apply brake pedal until vacuum is depleted from brake brake booster (firm pedal is obtained).

2. With parking brake fully released, turn ignition to "On". DO NOT START ENGINE.

a. If the "Brake" warning light turns "On" in 15 to 45 seconds, no further action is required, except to install a Campaign Identification label, part C of this procedure.

TEXT ZONE

B. Low Vacuum Module Installation ------------------------------

1. Disconnect cable from battery.

2. Remove right lower instrument panel insulator panel.

3. Remove and discard ECM harness shield. Refer to Figure 1.

4. Plug low vacuum module into its wiring connector. Refer to View A of Figure 1.

5. Tape module to ECM harness, as shown in View A.

6. Reinstall insulator panel.

7. Reconnect battery cable.

8. Repeat step 2 of "inspection" procedure to ensure the low vacuum warning system operates, and correct as required.

9. Install Campaign Identification label.

C. Campaign Identification Label Installation ------------------------------------------

Each vehicle modified in accordance with the instructions outlined in this procedure will required a Campaign Identification label. Each label provides a space to include the campaign number, the five (5) digit dealer code of the dealer performing the campaign service, and the date vehicle was campaigned. This information may be inserted with a typewriter or ballpoint pen. When installing label, clean the surface of the radiator upper mounting support and apply the campaign label where it is readily visible.

PARTS INVOLVED

Low vacuum brake module, part number 25516367, is to be obtained from WDDGM.

DO NOT ORDER A PART UNLESS YOU HAVE A VEHICLE TO CAMPAIGN AS VERY FEW VEHICLES ARE INVOLVED.

So that parts will be obtained as soon as possible, they should be ordered from WDDGM on a C.I.O. order with NO special instruction code, but order on an advise code (2).

WARRANTY CLAIM INFORMATION

Operation Failure Code Labor Operation Labor Hours ---------- ------------ --------------- -----------

Inspection Only 96 V3140 .2 Inspect and Install 96 V3141 .4 Module

.1 hour for clerical administration may be added to the above operation.

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.