ENGINE CHUGGLE AT LOW SPEEDS RAISE (TCC) LOCK-UP SPEED

SUBJECT: ENGINE CHUGGLE AT LOW SPEEDS (RAISE TORQUE CONVERTER CLUTCH (TCC) LOCK UP SPEED)

VEHICLES AFFECTED: 1989-91 J CAR W/2.0L, 1989 N CAR W/2.SL

THIS BULLETIN HAS BEEN REVISED TO INCLUDE THE 1990 AND 1991 J CAR WITH 2.0L ENGINE.

Condition:

---------- Some owners of 1989-91 J cars with 2.0L VIN 'K' and 1989 N cars with 2.5L VIN 'U' engines may comment of an engine shudder or chuggle condition when driving at slow speeds in high gear.

Cause:

------ Converter clutch lock up at slow speeds during some driving conditions.

Correction:

------------ A new PROM package has been released which raises the TCC lockup speed to the following:

1989 - 1991 J-Car with 2.0L - VIN CODE 'K' ------------------------------------------- From 37 to 63 KPH (23 to 39 MPH)

Usage PROM Pkg P/N Broadcast Code Scanner I. D. ------ ------------ --------------- -------------- All 16157159 AWSP 7171

1989 N-car with - 2.5L engine - VIN CODE 'U' ---------------------------------------------- From 47 to 69 KPH (29 to 43 MPH)

Usage PROM Pkg P/N Broadcast Code Scanner I.D. ------ ------------- -------------- ------------- All 16157765 AWDT 7781

Parts are currently available from CANSPO.

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.