What exactly does a Trans Relearn do, and how long does it usually take for it to learn?
SERVICE FAST LEARN ADAPTS
Service Fast Learn Adapts is a procedure for 6 speed automatic transmissions in which a series of tests are run to allow the transmission control module (TCM) to learn individual clutch characteristics. Once the clutch data is learned, Service Fast Learn Adapts translates it into the adaptive data cells, which the TCM uses for clutch control during shifts. The scan tool provides initiation of the Service Fast Learn Adapts procedure. This procedure is to be used following transmission repair.
The Service Fast Learn Adapts procedure must be performed when one of the following repairs have been made to the vehicle. Failure to perform the procedure after one of the following repairs may result in poor transmission performance, as well as transmission DTCs being set:
Transmission internal service/overhaul
Valve body repair or replacement
Control solenoid (w/body and TCM) valve assembly replacement
TCM software/calibration update
Any service in response to a shift quality concern
Justin
@BlackBearPerf did it to mine twice during the tune and it made for some freaky feeling 1-2 shifts, like a long slide into 2nd.