Radiator Cooling Fan Control System Check

Radiator Cooling Fan Low, Mid and High Speed Control System Check

Wiring Diagram








Troubleshooting

WARNING: Keep hands, tools, and clothing away from radiator cooling fan to prevent personal injury. This fan is driven by electric motors that can turn on whether or not the engine is running. The fan motor can start automatically in response to the ECT sensor signal if ignition switch is at "ON" position.

NOTE:
^ Radiator cooling fan low speed control takes place as follows: If engine coolant temperature becomes 102 degrees C or higher with engine at idle, radiator fan relay No.1 turns on and then radiator fan motor No.1 and No.2 run at low speed. When the coolant temperature becomes 99 degrees C or lower, both fan motors stop operating.
^ Radiator cooling fan mid and high speed control takes place as follows: If engine coolant temperature becomes 106.5 degrees C or higher with engine at idle, radiator fan relay No.3 turns on and then radiator fan motor No.1 runs at high speed. With delay of 0.3 second after start of radiator fan motor No.1, radiator fan relay No.2 turns on and then radiator fan motor No.2 runs at high speed. When engine coolant temperature drops to 103.5 degrees C or lower, high speed control is switched to low speed control.
^ Before performed troubleshooting, be sure to read Precautions of ECM Circuit Inspection:N32A.
^ When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect special tool between ECM and ECM connectors.

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