Radiator Fan System: Inspection

WARNING: This page is about a different variant/trim than selected.

DETECTING CONDITION:

Engine coolant temperature is more than 93°C (199°F).
A/C switch is OFF.
Vehicle speed is below 19 km/h (12 MPH).

TROUBLE SYMPTOMS:

Radiator main fan and sub fan do not rotate under the above conditions.

TROUBLE SYMPTOMS REFERENCE

Step	Check	Yes	No
1. CHECK MAIN FAN RELAY Turn the ignition switch to OFF. Remove the main fan relay 1 from A/C relay holder. Measure the resistance of terminal in main fan relay 1 switch.	Is the resistance more than 1 MΩ?	Go to step 2.	Replace the main fan relay 1.
2. CHECK MAIN FAN RELAY 1. Connect the battery to terminal of main fan relay 1 coil. Measure the resistance between terminals of main fan relay 1 switch.	Is the resistance less than 1 Ω?	Go to step 3.	Replace the main fan relay 1.
3. CHECK POWER SUPPLY TO ECM. Turn the ignition switch to OFF. Disconnect the connector from ECM. Turn the ignition switch to ON. Measure the voltage between ECM terminal and chassis ground. Connector & terminal (B135) No. 30 (+) - Chassis ground (-):	Is the voltage more than 10 V?	Go to step 4.	Repair the power supply line.
4. CHECK POWER SUPPLY TO RADIATOR FAN CONTROL UNIT. Turn the ignition switch to OFF. Connect the connector to ECM. Disconnect the connector from radiator fan control unit. Turn the ignition switch to ON. Measure the voltage between radiator fan control unit terminal and chassis ground. Connector & terminal (F106) No. 1 (+) - Chassis ground (-):	Is the voltage more than 10 V?	Go to step 5.	Repair the power supply line.
5. CHECK HARNESS BETWEEN ECM AND RADIATOR FAN CONTROL UNIT. Turn the ignition switch to OFF. Disconnect the connector from ECM. Measure the resistance between radiator fan control unit and ECM connector. Connector & terminal (B134) No. 31 - (F106) No. 2:	Is the resistance less than 1 Ω?	Go to step 6.	Repair the open circuit in harness between ECM and radiator fan control unit.
6. CHECK RADIATOR FAN CONTROL UNIT AND GROUND CIRCUIT. Connect the connector to ECM and radiator fan control unit. Measure the resistance between radiator fan control unit connector and chassis ground. Connector & terminal (F106) No. 3 - Chassis ground:	Is the resistance less than 5 Ω?	Go to step 7.	Repair the open circuit in harness between radiator fan control unit connector and chassis ground.
7. CHECK FAN MOTOR. Disconnect the connector from radiator fan control unit. Connect the battery positive (+) terminal to terminal No. 1, and the ground (-) terminal to terminal No. 3 of radiator fan control unit.	Does the fan motor rotate?	Go to step 8.	Replace the fan motor which does not rotate.
8. CHECK ECM OUTPUT SIGNAL Turn the ignition switch to OFF. Connect the test mode connector. Turn the ignition switch to ON. Using the oscilloscope, check the output signal. < Ref. to , RADIATOR FAN CONTROL OUTPUT WAVEFORM , Radiator Fan System. > Connector & terminal (B134) No. 31 (+) - Chassis ground (-):	Is the waveform output?	Replace the radiator fan control unit. < Ref. to , RADIATOR FAN CONTROL UNIT . >	Replace the ECM, < Ref. to ENGINE CONTROL MODULE (ECM) . >