COOLING FAN SYSTEM ON-VEHICLE INSPECTION


  1. CHECK COOLING FAN SYSTEM


    1. Check the operation of the cooling fan.


      1. Connect the intelligent tester to the DLC3.

      2. Turn the engine switch on (IG).

      3. Enter the following menus: Powertrain / Engine / Active Test / Control the Electric Cooling Fan.

      4. Check the operation of the cooling fan while operating it using the intelligent tester.

        If the cooling fan motor does not operate, check the cooling fan circuit Click here.

    2. Check the input signal and output current.

      Tech Tips

      Be sure to perform the inspection with the engine coolant temperature less than 92°C (198°F).


      1. Connect the 400 A probe of an ammeter to the cooling fan motor (M+), and then to the No. 2 cooling fan motor (S+) on the wire harness side.

      2. Using an oscilloscope, check the waveform between terminals A5-19 (RFC) and E6-1 (E1) of the ECM.

        A0162QPE10
        Standard Waveform
        Condition Input Signal Output Current

        Engine stopped

        (engine switch on (IG))

        Waveform 1

        (Duty ratio 0%)

        		 (Fan stops)

        Engine idling

        (A/C OFF)

        Waveform 1

        (Duty ratio 0%)

        		 (Fan stops)

        Engine idling

        (A/C ON)

        Waveform 2

        (Duty ratio 50 to 70%)

        2 to 22 A for cooling fan motor

        2 to 22 A for No. 2 cooling fan motor

        (Fan operates)

        Engine idling

        (engine coolant temperature sensor connector disconnected)

        Waveform 3

        (Duty ratio 50 to 70%)

        2 to 22 A for cooling fan motor

        2 to 22 A for No. 2 cooling fan motor

        (Fan operates)

        • 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 or cooling fan motor Click here.