Cold Idle Fluctuation at Altitude, Hesitation on Acceleration or 1-2 Upshift Delay (Reprogram PCM)
| Subject: | Cold Idle Fluctuation at Altitude, Hesitation on Acceleration or 1-2 Upshift Delay (Reprogram PCM) |
| Models: | 2002 Chevrolet Trailblazer |
| 2002 GMC Envoy |
| 2002 Oldsmobile Bravada |
| with 4.2L Engine (VIN S - RPO LL8) |
This bulletin is being revised to update the warranty information. Please discard Corporate Bulletin Number 03-06-04-018 (Section 06-Engine).
Condition
Some customers may comment on one of the following conditions:
| • | Idle fluctuation for a few seconds on the first start up after an overnight soak at higher altitudes. |
| • | Hesitation on acceleration, this typically occurs with engine coolant temperatures between 60-80°C (140-175 °F). |
| • | 1-2 upshift delay at throttle openings of 25% or less and ECT between 7-30°C (45-85°F). |
Cause
The existing PCM calibration may not be optimized for all conditions.
Correction
Reprogram the PCM with the latest service calibration available from Techline.
The Calibrations are electronic calibrations and are NOT available from GMSPO. Calibrations were available from Techline starting February 22, 2003, on the TIS 2000 version 2.5 for 2003 data update or later.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
J6354 | Engine Control Module - Reprogram | 0.4 hr |
