Engine - Chuggle At Low Speeds

91ponitac03

Bulletin Number: 91-6-23
Reference Number: 036515R
Publish Date: 2/91


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

Models

Affected: 1989-91 SUNBIRD W/2.0L, 1989 GRAND AM W/2.5L


This bulletin has been revised to include the 1990 and 1991 Sunbird with 2.0L engine. This bulletin cancels and replaces bulletin 89-6-86 issued 9/90.

Condition:

Some owners of 1989-91 Sunbird models with 2.0L and 1989 Grand Am models with 2.5L 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 Sunbird with 2.0L

From 23 to 39 MPH

Usage PROM Pkg P/N Broadcast Code Scanner I.D.


All 16157159 AWSP 7171


1989 Grand Am with 2.5L

From 29 to 43 MPH

Usage PROM Pkg P/N Broadcast Code Scanner I.D.

All 16157765 AWDT 7781

Parts are currently available from GMSPO.

Labor Operation Number : T0500
Labor Time : .4 - Grand Am
.3 - Sunbird