COOLING FAN ECU ON-VEHICLE INSPECTION

PROCEDURE

  1. INSPECT COOLING FAN ECU

    1. Check and ensure the following conditions:

      1. The power switch is off.

      2. The engine coolant temperature is less than 92°C (198°F).

      3. The auxiliary battery voltage is between 11 to 14 V.

      4. The A/C switch is off.

    2. Connect the pickup of a clamp-on ammeter around 1 of the 2 wires for the cooling fan motor.

    3. Turn the power switch on (IG) and wait for approximately 10 seconds. Check that the fan does not operate.

    4. Start the engine. Check that the fan does not operate with the engine idling.

      Tip:

      • Make sure that the engine coolant temperature is less than 92°C (198°F).

      • Turn the A/C switch off.

    5. Check that the fan operates when the A/C switch is turned on.

      Standard Current

      Table 1. w/ Towing Package

      Item

      Condition

      Specified Condition

      Cooling fan motor

      Auxiliary battery voltage applied at 20°C (68°F)

      15.5 to 21.5 A

      No. 2 cooling fan motor

      15.5 to 21.5 A
      Table 2. w/o Towing Package

      Item

      Condition

      Specified Condition

      Cooling fan motor

      Auxiliary battery voltage applied at 20°C (68°F)

      10.6 to 16.6 A

      No. 2 cooling fan motor

      10.6 to 16.6 A
      Tip:

      Make sure that the engine coolant temperature is less than 92°C (198°F).

    6. Check that the fan operates when the engine coolant temperature sensor connector is disconnected.

      Standard Current

      Table 3. w/ Towing Package

      Item

      Condition

      Specified Condition

      Cooling fan motor

      Auxiliary battery voltage applied at 20°C (68°F)

      15.5 to 21.5 A

      No. 2 cooling fan motor

      15.5 to 21.5 A
      Table 4. w/o Towing Package

      Item

      Condition

      Specified Condition

      Cooling fan motor

      Auxiliary battery voltage applied at 20°C (68°F)

      10.6 to 16.6 A

      No. 2 cooling fan motor

      10.6 to 16.6 A
    7. A284427C02

      *a

      Operating Diagram

      *b

      A/C OFF

      *c

      MAX HI

      *d

      HI

      *e

      LO

      *f

      MAX LO

      *g

      Fan Speed

      After the engine is warmed up, check that the fan operates as shown in the illustration.

      Tip:

      • The engine coolant temperature at which the fan starts operating is approximately 94°C (201°F).

      • This system can also be checked using the GTS.

      • Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

      Powertrain > Engine and ECT > Data List

      Tester Display

      Coolant Temp