General Information

The automatic transaxle as well as the engine is controlled by a powertrain control module (PCM). Part of the PCM is dedicated to the operation of the automatic transaxle referred to as the transaxle controller (TC).

The PCM/TC uses various input and output parameters to control the transaxle shifts. The PCM/TC has the ability to adjust (adapt) the shifting pressures due to build variations, normal transaxle wear, and environmental conditions.

Along with controlling the transaxle, the PCM/TC also incorporates extensive built-in diagnostics which constantly monitors the transaxle operation. When certain fault conditions are detected the PCM will store a diagnostic trouble code and illuminate the MIL telltale lamp to notify the driver that a fault condition has occurred. Some detected faults will not turn on an indicator lamp, but will store an information flag in the PCM to aid in diagnosing a problem. The diagnostic trouble codes and information flags which get stored into the PCM/TC are designed to determine when mechanical faults as well as electrical faults have occurred.