Radiator Cooling Fan High Speed Control System Check: Troubleshooting

WARNING: Keep hands, tools, and clothing away from radiator cooling fan to help prevent personal injury. This fan is electric and can come on whether or not the engine is running. The fan can start automatically in response to the ECT sensor with the ignition switch at the "ON" position.

NOTE:

Before performed troubleshooting, be sure to read the PRECAUTIONS OF ECM CIRCUIT INSPECTION .
When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special tool to ECM and/or the ECM connectors referring to INSPECTION OF ECM AND ITS CIRCUITS .

TROUBLESHOOTING PROCEDURES

Step	Action	YES	NO
1	Low speed radiator cooling fan control circuit check Check low speed radiator cooling fan control circuit referring to RADIATOR COOLING FAN LOW SPEED CONTROL SYSTEM CHECK . Is it in good condition?	Go to Step 2.	Repair or replace faulty condition.
2	High speed radiator cooling fan control circuit check Start engine and select "Data List" mode on scan tool. Warm up engine until coolant temp. is 102.5 °C, 216.5 °F or higher and A/C switch turns OFF. (If engine coolant temp. dose not rise, check engine cooling system or ECT sensor.) Is radiator cooling fan started at high speed when engine coolant temp. reached above temp?	Radiator cooling fan control system is in good condition.	Perform from Step 2 to Step 6 of DTC P0480: FAN 1 CONTROL CIRCUIT . If OK, Go to Step 3.
3	Radiator cooling fan check Check radiator cooling fan referring to RADIATOR COOLING FAN ASSEMBLY INSPECTION . Is it in good condition?	Substitute a known-good ECM and recheck.	Faulty radiator cooling fan.