ENGINE CHUGGLE AT LOW SPEEDS NEW PROM PACKAGE

SUBJECT: ENGINE CHUGGLE AT LOW SPEEDS (NEW PROM PACKAGE TO RAISE TCC LOCKUP SPEED)

VEHICLES AFFECTED: 1990 N CARS W/2.5L (VIN 'U') AND 3T40 A/T)

CONDITION:

---------- Some owners of 1990 N-cars with 2.5L engines may comment about an engine shudder or chuggle condition when driving at slow speeds in high gear.

CAUSE:

------ Converter clutch lockup at slow speeds during some driving conditions.

CORRECTION:

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

1990 N-Car With 2.5L Engine (From 47 to 69 kph)

Usage PROM Pkg. P/N Broadcast Code Scanner I.D. ----- -------------- ------------- ------------ All 16159793 AXCM 9801

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.