2006-2007 G Van Surge At 51 To 64 MPH - keywords 6.6 4L85E accel accelerate cal calibrate calibration chuggle ECM engine hesitate LLY MN8 PCM stumble throttle update
| Subject: | 2006-2007 G Van Surge at 51 to 54 MPH |
| Models: | 2006-2007 Chevrolet Express |
| 2006-2007 GMC Savana |
| Equipped with the 6.6 Duramax Diesel Engine RPO code LLY |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
A dealer may encounter a 2006 to 2007 Chevrolet Express or GMC Savana Van with a surge at 51 to 54 MPH (82 to 86 KPH).
The surge may be more prevalent at altitudes of 1500 feet (457 meters) or higher, but may be noticed below 1500 feet.
Recommendation/Instructions:
Complete the current SI diagnostics for any trouble code or symptom found. If there are no DTCs, and diagnostics are inconclusive there has been a new calibration released for a 51 to 54 MPH engine surge.
The surge addressed by this calibration is very specific to the 51 to 54 MPH range. If the TCC is disengaged the surge may not be felt.
If the engine speed is monitored a fluctuation of around 100 RPM may be noticed.
If a 51 to 54 MPH surge has been verified install the latest TIS2000 calibration titled "Addresses vehicle surge complaint between 51-54 mph at altitudes at or above 1500 feet"
Evaluate the surge after the new calibration is installed.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
