Component Tests and General Diagnostics

On-vehicle inspection

1. INSPECT COOLING FAN OPERATION AT LOW TEMPERATURES (Below 92 °C (198 °F))
(1) Turn the ignition switch to ON.
(2) Check that the cooling fans stop.
If it does not, check the cooling fan relays and engine coolant temperature sensor, and check whether there is a disconnection or an open circuit between them.
(3) Disconnect the engine coolant temperature sensor connector.
(4) Check that the cooling fans operate.
If it does not, check the fuses, cooling fan relays, ECM and cooling fans, and check for a short circuit between the cooling fan relays and the engine coolant temperature sensor.
(5) Reconnect the engine coolant temperature sensor connector.
2. INSPECT COOLING FAN OPERATION AT HIGH TEMPERATURES (Above 95 °C (203 °F))
(1) Start the engine, and raise the engine coolant temperature to above 95 °C (203 °F).

NOTE:
The engine coolant temperature is detected by the engine coolant temperature sensor on the water outlet.

(2) Check that the cooling fans operate.
If it does not, replace the engine coolant temperature sensor.