CRUISE CONTROL RESPONSE MODULE MAY BE REPLACED

Model and Year: 1988 G20 VANS WITH 6.2L DIESEL ENGINE AND (K34) CRUISE CONTROL

Some 1988 G Vans equipped with 6.2L light duty Diesel engines (LH6) and cruise control may exhibit a condition involving cruise control response. Accelerating and/or decelerating several mph more than anticipated may occur when the driver uses the Set, Resume, Tap-up, Tap-down, Coast, or Accelerate cruise modes. This may be caused by negative voltage transients during glow plug operation.

A cruise control module which is less susceptible to negative voltage transients may be installed.

VEHICLES INVOLVED

1988 Chevrolet G20 vans equipped with 6.2L light duty diesel engines (LH6) and cruise control (K34) built within the following VIN breakpoints:

From Through

J4503836 J4509848

PARTS

Part Name Part Number Quantity --------- ----------- -------- Cruise Control Module 25074713 1

SERVICE PROCEDURE

Cruise control module replace. (Refer Figure 1)

1. Disconnect cruise harness (121). 2. Disconnect module assembly (116) by prying back the retaining clip on the bracket and sliding the module out. 3. Install new module part #25074713. 4. Connect cruise harness.

The labor operation to replace the cruise control module is:

Labor Operation: R1220 Labor time: .3 Hrs.

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.