Radiator Cooling Fan Control Module: Testing and Inspection
COOLING FAN ECUON-VEHICLE INSPECTION
1. CHECK COOLING FAN ECU
(a) Check the input signal and output current.
HINT: Be sure to perform the inspection with the radiator coolant temperature less than 82°C (180°F).
Wire Harness Side:
(1) Set the oscilloscope probe to the terminal B3-2 (SI) of cooling fan ECU.
(2) Connect the intelligent tester to the DLC3.
(3) Using the intelligent tester, check the waveform.
Standard waveform:
If the input signal is abnormal, there is a malfunction in the ECM or cooling fan ECU.
If the output current is abnormal even when the input signal is normal, there is a malfunction in the cooling fan ECU (SI) or motor.
(b) Check the cooling fan motor.
(c) Check the cooling fan motor operation.
(1) Disconnect the B3 cooling fan ECU connector.
(2) Connect the battery to the cooling fan ECU of terminal 3 (+B1) and 1 (E1).
If they do not operation, replace the cooling fan ECU.