Technical - Lean Hesitation, Sag or Stumble When Coolant Temperature is Between -6 and +20 Degrees C (Reprogram PCM)
| Subject: | Lean Hesitation, Sag or Stumble When Coolant Temperature is Between -6 and +20°C (Reprogram PCM) |
| Models: | 2000 Chevrolet and GMC C/K Models (Silverado, Sierra, Suburban, Tahoe, Yukon, Yukon XL) |
| with 4.8 L, 5.3 L, or 6.0 L V8 Engine (VINs V, T, U -- RPOs LR4, LM7, LQ4) |
| and 4L60-E Automatic Transmission (RPO M30) |
This bulletin is being revised to add 6.0L (RPO LQ4) V8 Engine applications. Please discard Corporate Bulletin Number 00-06-03-009 (Section 06 -- Engine).
Condition
Some customers may comment on a lean hesitation, sag or stumble condition present during light to moderate throttle accelerations.
| • | The condition is usually present only on the first one or two accelerations. |
| • | The condition occurs when the coolant temperature is between -6 and +21°C (20 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
The Calibrations listed are electronic calibrations and are NOT available from GMSPO. Calibrations will be available from Techline starting December 2000, on the TIS 2000 version TIS 19.5/2001 data update or later.
The following calibration and software updates are available:
Old Calibration P/N | New Calibration P/N | Vehicle | Engine/RPO | Other |
|---|---|---|---|---|
9357665 | 9358501 | 2 and 4 WD 1/2 ton PU | 4.8 L LR4 | w/ Harrison A/C Compressor |
9357697 | 9358502 | 2 and 4 WD 1/2 ton PU | 4.8 L LR4 | w/ Denso A/C Compressor |
9357705 | 9358503 | 2 WD 1/2 ton Utility | 4.8 L LR4 | w/ Traction Control |
9357667 | 9358504 | 2 WD 1/2 ton Utility | 4.8 L LR4 | w/o Traction Control |
9357671 | 9358505 | 2 and 4 WD 1/2 and 3/4 ton PU | 5.3 L LM7 | w/ Harrison A/C Compressor |
9357700 | 9358506 | 2 and 4 WD 1/2 and 3/4 ton PU | 5.3 L LM7 | w/ Denso A/C Compressor |
9357625 | 9358507 | 2 and 4 WD 1/2 ton Utility | 5.3 L LM7 | w/o Traction Control |
9357702 | 9358508 | 2 and 4 WD 1/2 ton Utility | 5.3 L LM7 | w/ Traction Control |
9357668 | 9358559 | 2 and 4 WD 3/4 ton PU | 6.0 L LQ4 | Fed. and Calif. Emis. Less than 8500 GVW |
9357669 | 9358560 | 2 WD 3/4 ton PU | 6.0 L LQ4 | Fed. and Calif. Emis. Greater than 8500 GVW |
9357706 | 9358561 | 2 and 4 WD 3/4 ton Utility | 6.0 L LQ4 | Fed. Emis. w/ETC Greater than 8500 GVW |
9357646 | 9358562 | 2 and 4 WD 3/4 ton Utility | 6.0 L LQ4 | Fed. Emis. w/o ETC Greater than 8500 GVW |
9357647 | 9358563 | 2 and 4 WD 3/4 ton Utility | 6.0 L LQ4 | Clean Fuel Fleet Emis. w/ETC Greater than 8500 GVW |
9357707 | 9358564 | 2 and 4 WD 3/4 ton Utility | 6.0 L LQ4 | Calif. Emis. w/o ETC Greater than 8500 GVW |
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
J6355 | PROM, Reprogramming Add: Diagnosis | Use Published Labor Time |
