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

Engine Coolant Temperature (ECT) Sensor:

PURPOSE
The Engine Coolant Temperature (ECT) sensor detects coolant temperature throughout the engine operating ranges. This information to the Powertrain Control Module (PCM) calculates the fuel injection amount, ignition timing, low/high speed cooling fan controls, IAC BPA control, and emission controls.

OPERATION
This is a negative temperature coefficient sensor; as temperature increases, resistance decreases.