SURGE AFTER TCC ENGAGEMENT NEW PROM P/N'S LISTED. GMC Truck Caballero 1986

For 1990-2009 cars

# SURGE AFTER TCC ENGAGEMENT NEW PROM P/N'S LISTED

#### VEHICLES AFFECTED: 1986 'G' AND 'G' SPECIALS WITH 5.0L ENGINES (LG4) AND THM-200-4R TRANSMISSIONS (ENGINE CODE H)

On some 1986 "G" and "G" Special with the 5.OL (LG4) engine and 4 speed automatic transmission (MW9) may experience the following customer comments of: 1. Surge after TCC lock-up. 2. Detonation on light acceleration. 3. False Code 53 - EGR Control Error.

If normal service procedures in the Shop Manual do not correct, a new service PROM with revised calibration is now available.

The model application are:

Year Model Engine Trans. Emissions Service PROM P/N

1986 G and G 5.OL 4 Spd. Auto. California 1228478 Special

1986 G and G 5.OL 4 Spd. Auto. Federal 1228479 Special

Use applicable labour time and operation numbers.

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.