SPARK KNOCK OR DETONATION REVISED ESC CALIB. IN PROM P/N

PARK KNOCK OR DETONATION NOISE

1987 OVERHEAD CAM L-4 TURBO ENGINE (VIN CODE M) IN SUNBIRD AND GRAND AM MODELS

Improvements made in the 1988 L-4 turbo electronic spark control (ESC) calibration are being made available to the 1987 L-4 turbo package.

Owner comments of a warmed-up spark knock or detonation noise are repaired with the following "more responsive ESC" PROM calibration:

Pontiac Sunbird and Grand Am Auto. Trans. P/N 16120036

For other ignition related conditions, refer to Service Manual Section 6D4 or 6E.

Use applicable Labor Time and Operation Number.

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.