Intermittent Power Loss And Rough Idle With No DTCs - keywords abuse accel acceleration cal calibrate calibration controls D3 drive DTC DTCs engine garage lack low management mode no nopower PCM range

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

On rare occasions, an intermittent lack of power and rough idle may be experienced with no DTCs. Some customers may advise that their vehicle will not exceed 20 MPH in first gear. Typically, this will only occur if the driver starts the engine, immediately places the shifter into D3, and accelerates - all within a couple of seconds. If this sequence of events occurs at a slower pace, this concern will not occur. Due to the shifter release mechanism being on the front of the shifter, the shifter may easily be placed into D3 instead of D4 when rapidly pulling back on the shifter and release mechanism. As a result, some customers may not realize that the shifter was in D3 when this occurred.

When this occurs, the PCM may intermittently enter transmission abuse management mode, which will limit the TP desired and actual angles to a maximum of 45% even if the accelerator pedal is pushed to wide open throttle. Rather than coming out of this mode though, the PCM will stay in this mode until the ignition is cycled, or until the shifter is moved to Park, Reverse, or Neutral and then back into D4.

If the SI diagnostics do not isolate a cause for this concern, reprogram the PCM with the latest TIS2Web calibrations and evaluate the concern. At this time, the latest calibrations are titled "New calibration to address customer complaint of intermittent no crank, also improves transmission performance in garage shifts." This calibration, or any that follow, is designed to address this concern.

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.