Theory Of Operation

The purpose of the monitoring is to check whether the coating temperature of a clutch is above three critical calibrated temperature thresholds. The clutch temperature is calculated using a temperature model in the Transmission Control module (TCM) which is based upon input speed and output speed, current gear and target gear, calculated effective pressure on engaging clutch and on disengaging clutch. The fault codes set by this diagnostic are used to protect the durability of the clutches by controlling the shift operation. No repair action is required. This fault is only used to initiate a calibration strategy and for diagnostic information in case other faults are set.