Engine - High Idle Upon Initial Shift Into Drive Gear
88buick09Bulletin: 88-6E-17
Date: July, '88
Ref. No.: 88-150-6E
Corp. Ref. No.: 836510R
SUBJECT: HIGH IDLE ON INITIAL SHIFT INTO DRIVE GEAR
MODELS AFFECTED: 1987 AND EARLY 1988 SKYHAWKS WITH 2.0L 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 2.0L (K) All 16086856
1988 Skyhawk 2.0L (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.