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

Testing Water Thermoswitch:

1. Remove switch from radiator and place in a container with water and a thermometer.
2. Gradually heat water and check that switch continuity does not exist until temperature rises above approximately 17°C (63°F).
3. If not correct, replace water temperature switch.

Water temperature switch input can be checked at ECU terminal 1Q. With radiator coolant temperature above 17°C (63°F), terminal voltage should be approximately 12V. With temperature below 17°C (63°F), voltage should be less than 1.5V.