Cooling Fan Control Inspection

1. Verify that the engine is cold.
2. Turn the ignition switch to ON.
3. Verify that the cooling fan is not operating.
- If the cooling fan is operating, proceed to next step.




4. Connect the SSTs (NGS tester) to the DLC-2.
5. Select the PID/DATA MONITOR AND RECORD function on the NGS display.

6. Using "FAN 1" and "FAN 2", verify that the cooling fan control signal is off.
- If the cooling fan control signal is on, inspect the PCM terminal voltage.
- Engine coolant temperature signal

NOTE:
- If the cooling fan control signal is OFF when the engine is hot, inspect the following.
- Fan relay
- Short circuit in wiring harnesses and connectors (Main relay - Fan relay - PCM)

CAUTION: Connecting the wrong DLC terminal may possibly cause a malfunction. Carefully connect the specified terminal only.




7. Short the DLC terminal TEN to body GND using a jumper wire.

8. Depress the accelerator pedal and verify that the cooling fan operates.
- If the cooling fan does not operate, proceed to next step.

9. Connect the SSTs (NGS tester).
10. Select the SIMULATION TEST function on the NGS display.

11. Turn the fan relay from OFF to ON using "FAN 1 and "FAN 2" and inspect for the cooling fan operation.
- If the cooling fan operates, inspect the following.
- PCM terminal voltage
- Diagnostic test mode signal
- Closed throttle position signal

- If the cooling fan does not operate, perform as follows.
1. Turn the fan relay from OFF to ON using the simulation function. Operate the fan relay and inspect if the operation sound of the relay is heard.
- If the operation sound is heard, check the fan motor and related harness.
- If the operation sound is not heard, check the cooling fan relay and related harness.