INTERMITTENT HIGH IDLE ON SHIFT TO DRIVE

MODELS AFFECTED: 1987 AND EARLY 1988 SKYHAWKS WITH 2.OL OHC L-4 ENGINES (VIN CODE K) AND AUTOMATIC TRANSMISSIONS

Customer comments of a higher than normal engine idle RPM upon initial drive gear engagement that decreases within a few seconds, may be because of an ECM software condition. This drive only RPM condition is similar to a "carbureted fast idle" or "high cam step" level.

The above condition may be brought on by repeated engine "revving" in park/neutral or by a rolling/stopping action while in neutral. This condition will only occur in a non A/C vehicle or with A/C off.

The following ECM calibration PROM's will help overcome the above condition:

SUSPECT* SERVICE CARLINE ENGINE (VIN) ECM PROM ------- ------------ --------- ------- 1987 Skyhawk 2.OL (K) All 16086856 1988 Skyhawk 2.OL (K) 16066512 16086129

In conjunction with this type of comment, stored diagnostic codes should be looked at as well as the symptom section of the Service Manual.

Use applicable labor operation and time.

* The suspect ECM part number can be checked by using a Tech 1 scanner.

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.