Radiator Cooling Fan: Testing and Inspection

Cooling Fan Control System Inspection




Cooling fan system operation (at idle)

1. Connect WDS or equivalent to DLC-2.
2. Verify that DTC P0480, P0481, and P0482 are not displayed.
- If DTC P0480, P0481 or P0482 are displayed, perform DTC inspection.

3. Verify that ECT PID is below cooling fan operating temperature.
4. Verify that the A/C switch and fan switch are off.
5. Start the engine and idle it.
6. Verify that the cooling fans are not operating.
- If cooling fan No.1 is operating, inspect whether cooling fan relay No.2 is stuck in the closed position.
- If the cooling fans are operating, inspect whether cooling fan relay No.1 is stuck in the closed position.
- If the cooling fans are operating at high speed, inspect DTC for ECT sensor (P0117, P0118).
- If cooling fan No.1 does not operate and cooling fan No.2 is operating, inspect whether cooling fan relay No.3 is stuck in the closed.

7. Start the engine.
8. Verify that the cooling fans are low speed when ECT PID is 100 °C {212 °F} or above.
- If cooling fan No.1 does not operate, verify that DTC P0480 is not detected.
- If DTC P0480 is detected, perform DTC inspection.
- If DTC P0480 is not detected, inspect for the following:
- Cooling fan relay No.2 is stuck in open position.
- Open circuit in wiring harnesses or connectors or both between cooling fan relay No.2 and cooling fan motor No.1.
- If the cooling fan No.2 does not operate, verify that DTC P0482 is not detected.
- If DTC P0482 is detected, perform DTC inspection.
- If DTC P0482 is not detected, inspect the following:
- Cooling fan relay No.3 is stuck in open position.
- Open circuit in wiring harnesses or connectors or both between cooling fan relay No.3 and cooling fan motor No.2

- If cooling fan No.1 or cooling fan No.2 or both are operating at high speed, verify that DTC P0481 is not detected.
- If DTC P0481 is detected, perform DTC inspection.
- If DTC P0481 is not detected, inspect the following:
- Cooling fan relay No.1 is stuck in closed position.
- Cooling fan relay No.4 is stuck in closed position.

9. Turn A/C switch and fan switch on.
10. Verify that A/C is operating.
- If A/C is not operating, inspect the following:
- A/C switch
- Fan switch
- Refrigerant pressure switch

11. Verify that cooling fan No.1 is operating at high speed and cooling fan No.2 is operating other than at low speed (high or middle speed).
- If the cooling fan relay does not operate high speed and cooling fan No.2 is operating low speed, inspect the following:
- Cooling fan relay No.1 is stuck in open position.
- Cooling fan relay No.4 is stuck in open position.