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

PURPOSE AND OPERATION
The engine coolant temperature sensor is located by the front left hand branch of the intake manifold. The sensor provides engine coolant information to the electronic control unit (ECU). The ECU 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 ECU applies a voltage signal to the coolant temperature sensor. The ECU detects a small current when the engine coolant is at a low temperature; it detects a larger current with a high temperature.