Engine - Idle Fluctuationr, RPM Hunting During Decel

File In Section: 6E - Engine Fuel & Emission

Bulletin No.: 67-65-29

Date: August, 1996

Subject:
Idle Fluctuation in Gear or RPM Hunting during Deceleration and Unstable Idle (Flash Calibration)

Models:
1996 Chevrolet Cavalier
1996 Pontiac Sunfire with 2.4L Engine (VIN T - RPO LD9) and Automatic Transmission only

Condition

Some owners may experience an idle fluctuation in drive or RPM "hunting" during deceleration after reaching normal operating temperature.

Cause

The PCM controlled closed loop idle system may be interacting with the generator load, resulting in corrections that appear as idle speed fluctuations.

Correction

A new calibration has been developed to stabilize the idle speed. This calibration should only be installed if the owner has indicated a concern with the vehicle idle stability or idle speeds.

Perform the PCM flash calibration procedure using the number 14 CD-ROM update or later version.

Correct calibration information is listed in the chart below.

Parts Information

Applications/ Broadcast Part Number
Emissions Code and Scan ID

Federal BZAZ 16249193
California BZBA 16249203
Export BZAY 16249183

Warranty Information

For vehicles repaired under warranty, use:

Labor Labor
Procedure Operation Hours

PROM Reprogramming, J6355 0.4 hr*
On Car

* Diagnosis time may be claimed for 0.0 to 0.7 hours depending on actual time performing diagnosis.