TCM Adaptation - 8HP45 /845RE / 8HP70: Notes

WARNING: This page is about a different car, the 2014 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.

The Transmission Control Module (TCM) or Transmission Control Module Assembly (TCMA) controls the fluid pressure and fill time of each clutch pack to give optimal shift quality. As the clutches wear, the TCM or TCMA will adapt and make adjustments to keep the shift quality consistent over the life of the vehicle. The initial clutch filling pressure and fill times are set at the factory. When a transmission assembly or transmission component is replaced, or when the adaptation values are reset, the adaptation values must be relearned. This procedure should also be followed when it is suspected that a vehicle has not been driven in a manner that encourages clutch adaptation learning in highway or city driving conditions.

The two procedures to relearn these values are called Fast Filling Adaptation and Standard Clutch Filling Adaptation. Depending on the repair or complaint, one or both procedures must be performed as described below.