ENGINE CHUGGLE AT LOW SPEEDS (NEW PROM TO RAISE TCC SPEED)

SUBJECT: ENGINE CHUGGLE AT LOW SPEEDS (NEW PROM PACKAGE TO RAISE TCC LOCK UP SPEED) (Revised to Change No. from 91-622-101 to 91-622-104)

VEHICLES AFFECTED: 1990 AND 1991 "J AND L" CARS WITH 2.2L AND A/T

Condition:

---------- Some owners of 1990 and 1991 J and L cars with 2.2L engines may comment of an engine shudder or chuggle condition when driving at slow speeds in high gear.

Cause:

------ Torque converter clutch locking up at slow speeds during some driving conditions.

Correction:

----------- A new PROM package has been released which raises the torque converter clutch lockup speed from 37 KM TO 46 KM (23 MPH to 35 MPH).

Car Eng Trans Emissions PROM Pkg Broadcast Scanner Body Type Type Type P/N Code I.D. ---- ---- ---- --------- -------- --------- ------- J 2.2L AUTO FEDERAL 16173383 BABH 3371 L 2.2L AUTO FEDERAL 16173385 BABK 3391

For vehicles repaired under warranty use:

Labour Time: .4 Hours "J" Car .5 Hours "L" Car

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.