Transaxle Control Module

NOTE: TCM may also be referred to as EATX module.

TCM may receive signal data in 2 ways: directly from a sensor or component, or through a twisted-pair bus circuit which connects all vehicle computer systems. This modulated bi-directional bus system is called Chrysler Collision Detection (CCD) bus and allows various vehicle control modules to share signal data. If a CCD bus failure exists, default values are substituted by the TCM, allowing continued, but limited operation.

Battery voltage is supplied to TCM. If TCM looses battery voltage, transaxle will enter limp-in mode. For additional information on limp-in mode, see LIMP-IN MODE . When TCM receives an ignition run signal from ignition switch, it performs a series of circuit and relay checks. If no problem is found, TCM provides voltage to transaxle control relay. This allows relay contacts to close, supplying voltage to solenoid assembly.

TCM contains an adaptive control method which learns application and release rates of transaxle components for smooth operation. TCM also learns the rate at which applied elements build pressure sufficient for a speed change.