ROUGH IDLE OR SEAT SHAKE (REVISED CALIBRATION)

Subject: ROUGH IDLE OR SEAT SHAKE

Model and Year: 1992 CORSICA AND BERETTA WITH 2.2L ENGINE AND AUTOMATIC TRANSMISSION

Condition: Some owners of 1992 "L" cars may comment of a rough idle or seat shake inside the car at idle.

Cause: Engine idle speed causing a harmonic resonance in the vehicle.

Correction: A revised calibration has been released to raise the engine idle speed in automatic transmission "L" cars from 600 to 800 rpm.

Install the appropriate calibration from the following chart with a T-100 (GM-CAMS) or a Tech 1 according to the User's Manual instructions provided with the cartridge.

The Tech 1 cartridge part number is TK06032A and should should have been sent to dealers on February 28, 1992. The calibrations will also be included in the January 1992 Software Update for the T-100.

Car Trans Emission Part Broadcast Scanner Body Type Type Number Code I. D. ---- ----- -------- ------ --------- ------- L Auto Federal 16176091 BATU 6091 L Auto Calif. 16176101 BATW 6101

Labor Operation Number: T0500 Labor Time: .3 Hours

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.