Cooling Fan Control Inspection

Cooling Fan Operation

Cooling fan relay

1. Verify the engine is cold.
2. Turn the ignition switch on.




3. Verify that the cooling fan is not operating.
- If the cooling fan is operating:
1. Connect the SST (NGS tester) to the DLC-2.
2. Select the SIMULATION TEST function on the NGS display.
3. Select IG ON TEST mode.
4. Select FAN 3 PID.




5. Send OFF and verify the cooling fan is off.
- If the cooling fan is on, inspect for the following:
- Cooling fan relay is stuck in closed position.
- Short to Ground circuit between cooling fan relay and PCM terminal 47
- Short to power in circuit at cooling fan relay
- DTC for ECT sensor (P0117, P0118, P0125)

- If the cooling fan is off, inspect the following:
- Short to Ground circuit between refrigerant pressure switch and PCM terminal 41
- DTC for ECT sensor (P0117, P0118, P0125)

4. Start the engine.

5. Verify that the cooling fan is operating when engine is hot.
- If the cooling fan does not operate, perform the following:.
1. Connect the SST (NGS tester) to the DLC-2.
2. Select the SIMULATION TEST function on the NGS display.
3. Select IG ON TEST mode.
4. Select FAN 3 PID.
5. Press START.

6. Verify that the cooling fan is operating.
- If the cooling fan operates, inspect the ECT sensor DTC (P0117,0118, P0125).

- If the cooling fan does not operate, perform the following:
1. Select FAN 3 PID.
2. Operate cooling fan by selecting START.

3. Verify that operation sound is heard from the cooling fan relay.
- If the operation sound is heard, inspect the wiring harness, connectors and cooling fan motor.
- If the operation sound is not heard, inspect cooling fan relay and open circuit in wiring harness and connectors.

6. Turn the A/C switch and fan switch on.
7. Verify that the cooling fan is operating.
8. If fan does not operate, inspect A/C system.