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

Engine Coolant Temperature (ECT) Sensor:

PURPOSE
The Engine Coolant Temperature (ECT) sensor constantly supplies the ECA with a signal reflecting engine coolant temperature. The ECA reads varying sensor resistance and determines engine operating temperature. This information is used in calculations for air/fuel mixture, idle speed, fuel pressure, EGR flow, and purge flow.

LOCATION
Near thermostat housing.

OPERATION
The ECT is a negative temperature coefficient sensor. As coolant temperature increases, sensor resistance decreases, and vice versa.