Due to the addition of "MODELS AFFECTED," this bulletin supersedes bulletin 91 - T - 06, which should be discarded.
PURPOSE: The transaxle controller (PCM/TC) has the ability to adjust (adapt) the shifting pressures due to build variations, normal transaxle wear, and environmental conditions. In order to prevent possible transaxle damage, or a customer concern, the adaptive parameters must be reset using the Service Stall System, whenever the following repairs are performed:
A. Replacing a transaxle
B. Replacing a line pressure actuator
C. Transaxle overhaul when new clutch plates are installed
D. Replacing a valve body
The vehicle must also be driven following the "Learn-In Procedure" (page TAAT 18) located in the "Powertrain Control Module-Transaxle Control" section of the March 1991 "Automatic Transaxle Service Manual."
The labor time for resetting adaptive parameters, as well as time for driving the vehicle, is included in the labor operation time for procedures "A" through "D" in this bulletin.
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.