Operation CHARM: Car repair manuals for everyone.

Engine - Coolant Temperature Sensor/Switch: Testing and Inspection

1. Check that radiator fan functions in the following manner.
MODELS EQUIPPED WITH A/C:
A/C switch Off, ignition switch On and coolant temperature below 95°C (205°F): No Operation.
A/C switch Off, ignition switch On and coolant temperature above 95°C (205°F): Fan Operates.
A/C switch On, ignition switch On and coolant temperature above or below 95°C (205°F): Fan Operates.
MODELS LESS A/C:
Ignition switch On and coolant temperature below 95°C (205°F): No Operation.
Ignition switch On and coolant temperature above 95°C (205°F): Fan Operates.
2. If radiator fan runs with coolant temperature below 95°C (205°F), Coolant Temperature Switch (CTS) has failed.