Adapt Function

Adapt Function
The Transmission Control Module (TCM) produces excellent shift quality by applying closed loop control that constantly adjusts shift characteristics for changes in operating conditions. These adjustments are based on vehicle conditions such as grade, load, and engine power.
The learning process of comparing and adjusting shift parameters is referred to as adaptive control. Adaptive control establishes initial conditions for shifts and makes "during shift" adjustments. The TCM constantly monitors operating conditions, such as battery voltage and transmission sump temperature, and adjusts shift parameters accordingly. After a shift is completed, the TCM compares the shift to a target shift profile in the TCM calibration and makes adjustments before the next shift of the same kind is made.
A new or newly rebuilt transmission must always have the TCM reset to base, which puts it into fast adaptive mode. When the TCM operates in this mode, it makes large changes in initial shift conditions to adjust for major system tolerances, such as solenoid-to-solenoid, main pressure, and clutch-to-clutch variations.
In slow adaptive mode, the TCM makes small changes in initial shift conditions in response to minor system changes that occur over a longer period of time such as wear and solenoid degradation or drift. The TCM control logic changes from fast adaptive to slow adaptive when the profile of an actual shift has effectively reached the target profile.

For additional information please refer to TSB #01-07-30-025