Engine Coolant Temperature (ECT) Sensor
WARNING: This page is about a different car, the 2005 Jaguar XJR, 2005 Jaguar XJ8, 2004 Jaguar XJR, and 2004 Jaguar XJ8. However, it is still accessible from the selected car via links, so may be relevant.
The engine coolant temperature (ECT) sensor detects engine coolant temperature and supplies the information to the TCM. The ECT sensor is used to control the torque converter clutch (TCC) operation.