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 SSTs (NGS tester) to the DLC-2.
2. Select the SIMULATION TEST function on the NGS display.
3. Select ignition 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 GND 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 GND 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 SSTs (NGS tester) to the DLC-2.
2. Select the SIMULATION TEST function on the NGS display.
3. Select ignition 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.

Condenser fan relay
1. Verify that A/C switch and fan switch are off.
2. Start the engine and let it idle.
3. Verify that the condenser fan is not operating.
- If condenser fan is operating, inspect for the following:
- Condenser fan relay is stuck in closed position.
- Short to power in circuit between condenser fan relay and condenser fan
- Short to GND in circuit between refrigerant pressure switch and PCM terminal 41
- Short to GND circuit between condenser fan relay and PCM terminal 45

4. Turn the A/C switch and fan switch on.
5. Verify that the condenser fan is operating and operation sound of A/C compressor magnetic clutch is heard.
6. Turn the A/C switch and fan switch off.
- If the condenser fan does not operate but operation sound of A/C compressor magnetic clutch is heard, inspect for the following:
- Open circuit between ignition switch and condenser fan relay
- Open circuit between battery and condenser fan relay
- Open circuit between condenser fan relay and PCM terminal 45
- Open circuit between condenser fan relay and condenser fan motor or fan motor GND
- Condenser fan relay for being stuck open.
- Condenser fan motor

- If both condenser fan and A/C compressor do not operate, inspect the following:
- TP V PID
- A/C system