Engine Coolant Temperature Sensor

Engine Coolant Temperature (ECT) sensor indicates engine coolant temperature to the TCM. When engine coolant temperature is cold, TCM may delay upshifts slightly to improve driveability. TCM prevents torque converter clutch lock-up until engine reaches normal operating temperature. If engine coolant temperature becomes excessively warm, TCM allows torque converter clutch lock-up to aid in engine cooling and prevent transaxle overheating.