Lean Hesitation, Sag or Stumble on Light/Moderate Acceleration (Reprogram PCM)
| Subject: | Lean Hesitation, Sag or Stumble On Light/Moderate Acceleration (Reprogram PCM) |
| Models: | 1999 Chevrolet and GMC C/K Pickup Models (Silverado, Sierra) |
| with 4.8 L, 5.3 L or 6.0 L V8 Engine (VINs V, T, U -- RPOs LR4, LM7, LQ4) |
Condition
Some customers may comment on the following condition:
A lean hesitation, sag or stumble present during light to moderate accelerations.
| • | Usually only present on the first one or two accelerations. |
| • | The condition occurs when the coolant temperature is between -6°C and +21°C (20°F and 70°F). |
| • | Fuels with a high driveability index can also be a contributor. |
Cause
Calibrations not optimized for various operating parameters.
Correction
Verify that the driveability condition is not the result of an inoperative component, or a related wiring/other condition.
Calibration Information
Old Calibration P/N | New Calibration P/N | Vehicle | Engine/RPO |
|---|---|---|---|
9357587 | 9358565 | 2WD and 4WD 1/2 ton PU | 4.8 L/ LR4 |
9357589 | 9358567 | 2WD and 4WD 1/2 ton PU | 4.8 L/ LR4 |
9357593 | 9358568 | 2WD and 4WD 1/2 and 3/4 ton PU | 5.3 L/LM7 |
9357595 | 9358570 | 2WD and 4WD 1/2 and 3/4 ton PU | 5.3 L/LM7 |
9357598 | 9358572 | 2WD and 4WD 3/4 ton PU | 6.0 L/LQ4 |
9357600 | 9358574 | 2WD and 4WD 3/4 ton PU | 6.0 L/LQ4 |
The Calibrations listed are electronic calibrations and are NOT available from GMSPO. Calibrations will be available from Techline starting November 2000, on the TIS 2000 version 19.5 TIS 00/2000 data update or later.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
J6355 | PROM Reprogramming Add: Diagnosis | Use Published Labor Time |
