Radiator Cooling Fan Low 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 CHART

Step	Action	YES	NO
1	Is there DTC(s) of ECT sensor circuit (DTC P0116 / P0117 / P0118) and/or radiator cooling fan circuit (DTC P0480 / P0481)?	Go to corresponding DTC flow.	Go to Step 2.
2	Low speed radiator cooling fan control circuit check Connect scan tool to DLC with ignition switch turned OFF. Start engine and select "Data List" mode on scan tool. Warm up engine until coolant temp. is 97 °C, 206.6 °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 low speed when engine coolant temp. reached above temp.?	Radiator cooling fan low speed 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 control check Disconnect radiator cooling fan relays No. 2 and No. 3 from fuse box No.2 with ignition switch turned OFF. Run engine when ECT is over 97 °C, 206.6 °F. Measure voltage between vehicle body ground and "BLU/RED" wire terminal of disconnected radiator cooling fan motor connector. Is voltage 10 - 14 V?	Go to Step 4.	"BLU/RED" wire is open or high resistance circuit.
4	Check radiator cooling fan wire circuit check Turn ignition switch to OFF position. Measure resistance between "BLK" wire terminal of disconnected radiator cooling fan motor connector and vehicle body ground. Is resistance below 1 Ω?	Go to Step 5.	"BLK" wire is open or high resistance circuit.
5	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.