LH6 Engine Low Speed Deceleration Shudder, Chuggle or Pulsation (Reprogram ECM)
| Subject: | LH6 Engine Low Speed Deceleration Shudder, Chuggle or Pulsation (Reprogram ECM) |
| Models: | 2006 Buick Rainier |
| 2006 Chevrolet TrailBlazer, TrailBlazer EXT |
| 2006 GMC Envoy Denali, Envoy XL Denali |
| 2006 Saab 9-7X |
| with 5.3L Vortec V8 Active Fuel Management Engine (VIN M -- RPO LH6) |
| and Two-Wheel Drive ONLY Vehicles with 4L60-E Automatic Transmission (PRO M30) |
| Attention: | The following service ECM calibration update may slightly increase fuel consumption and should only be used if the customer commented on the shudder conditions outlined in this Service Bulletin. Most vehicles will never experience this shudder. |
Condition
Some customers may comment on the following low speed deceleration shudder, chuggle or pulsation conditions:
| • | Shudder feels like a brake pulsation and/or chuggle on deceleration from approximately 40 km/h (25 mph) to 24 km/h (15 mph). |
| • | Shudder will continue if brakes are released and the vehicle coasts in 40 km/h (25 mph) to 24 km/h (15 mph) speed range. |
| • | Shudder is significantly diminished or eliminated if A/C is "Off" due to reduced engine load. |
| • | Shudder is eliminated if vehicle is put in D3 mode, which disables 4 cylinder mode (4 cyl mode is permitted when trans is automatically in 3rd or 4th gear, but disabled when PRNDL is placed in the 3rd position). |
Selectable Service Calibration Number
Important:: Use this selectable service calibration Only for vehicles with low speed deceleration shudder, chuggle and/or pulsation experienced at high temperature and low altitude. A slight increase in fuel consumption may occur.
Calibration 12614807 is selectable with 12606496. The title line states : "New calibration to address vehicle shudder during decel between 25 and 15 mph, feels like brake roughness. Should be used for complaint only as some loss of performance and fuel economy may occur."
Correction
Reprogram the ECM with the latest calibrations if the above concern is encountered. An updated ECM calibration is now available to address this concern. This calibration, or any that follow, is designed to address this concern. Refer to Service Programming System (SPS) using the appropriate Service Information (SI) procedures. The new ECM calibrations will be available to dealerships in TIS2Web (website version of TIS) version 10.0 for 2006 beginning 10/01/2006. If you cannot access the calibration, call the Techline Customer Support Center at 1-800-828-6860 (English) or 1-800-503-3222 (French) and it will be provided. As always, make sure your Tech 2® is updated with the latest software version.
Warranty Information (excluding Saab U.S. Models)
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
J6354 | Powertrain Control Module - Engine Reprogramming with SPS | Use Published Labor Operation Time |
Warranty Information (Saab U.S. Models)
For vehicles repaired under warranty, use:
Labor Operation | Description | Failed Object | Fault/Reason Code | Location Code | Warranty Type | Repair/Action Code | Labor Time |
|---|---|---|---|---|---|---|---|
2481001 | Powertrain Control Module - Engine Reprogramming with SPS | 24810 | 67 | 0 | 01 | 05 | Use Published Labor Operation Time |
