INCORRECT CRUISE CONTROL RESUME OPERATION

VEHICLES AFFECTED: ALL 1987-89 VEHICLES WITH CRUISE CONTROL OPTION (K34)

This bulletin pertains to 1987-89 A,B,C cars (for Buick and Oldsmobile), 1987-89 D,F,G,H,J,P and W cars (for Buick and Oldsmobile) and Chevrolet Y-cars. Also, 1987 C/K/R/V/G/M/S and T trucks.

This bulletin will help in diagnosing an intermittent condition which may otherwise be difficult to correct. This condition occurs only on vehicles using a "Multi-function" lever, with turn signal, beam change, wash/wipe, and cruise control functions, and on Cadillac D and Chevrolet Y, which do not use multi-function levers.

Condition:

--------- When using the cruise control resume switch the cruise control may resume to a new set speed that is different from the original set speed. If the new set speed is well below the original speed, this could also be reported as inoperative resume. The brake switch and the on/off switch still function properly to disengage the cruise control system. Another condition is that the resume/accel function may be totally inoperative, but the set/coast switch will still work.

These conditions usually occur with some accumulated mileage, depending on how often the cruise control system is used.

Cause:

----- An intermittent condition in the turn signal lever switch causes the cruise control system to set a new speed when the slider is moved to resume.

The intermittent condition is so short that it cannot be detected by normal methods, and the switch will test good.

Replace the switch (Multi-Function Lever) or turn signal lever on D and Y cars.)

Parts Information:

All parts in stock at CANSPO have been replaced with new part numbers. If replacing a switch for this condition, do not use parts in dealer stock. All new orders will automatically receive the new part numbers.

If a switch is being replaced for any other condition, switches in dealer stock may be used.

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.