PCM Learning Ability

On vehicles equipped with Automatic transaxles, the Transaxle Controller (TC) portion of the PCM also has a learning ability to achieve smooth shifts. If the battery is disconnected, the TC will lose the fine tuning of shift points, which has been learned while driving the vehicle. Connecting the battery will not reset the TCM adaptive parameters. The adaptives can only be reset using the Saturn Service Stall System (SSS). To relearn the shifts, the vehicle should be driven so that each shift is achieved at least twice.