Coolant Temperature Sensor/Switch (For Computer): Description and Operation

PURPOSE AND OPERATION
The Engine Coolant Temperature Sensor (ECTS) provides engine coolant information to the Engine Control Module (ECM). The ECM increases the injector opening time when cold to provide improved driveability, and reduces the opening time as the engine reaches normal operating temperature.

The Engine Coolant Temperature Sensor decreases its resistance as engine coolant temperature increases. The ECM applies a voltage signal to the Coolant Temperature Sensor. The ECM detects a small current when the engine coolant is at a low temperature; it detects a larger current with a high temperature.