Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection

NOTE: Bleed air from the cooling system after installing the engine coolant temperature (ECT) switch.

1. Remove the ECT switch from the thermostat housing.

Engine Coolant Temperature (ECT) Switch Test:

2. Suspend the ECT switch in a container of coolant as shown.
3. Heat the coolant, and check its temperature with a thermometer.

Engine Coolant Temperature (ECT) Switch Test:

4. Check for continuity between the A and B terminals according to the table.