Inspection Procedure 2: Radiator Fan and Condenser Fan do not Operate <4N1>

OPERATION

Based on the signal from the engine coolant temperature sensor and the signal from the wheel speed sensor signal (vehicle speed signal) from the ASC-ECU, and the A/C switch signal from the A/C-ECU, the engine-ECU sends the radiator fan and condenser fan control signal to the ETACS-ECU via CAN bus line.
Based on the radiator fan and condenser fan control signal from the engine-ECU, the ETACS-ECU turns ON/OFF the radiator fan relay, condenser fan relay, and the fan control relay to control the rotation of the radiator fan motor and condenser fan motor.

TECHNICAL DESCRIPTION

If the radiator fan and condenser fan do not operate, the radiator fan motor, the condenser fan motor, the radiator fan relay, the condenser fan relay, the fan control relay, the ETACS-ECU may be defective.
The CAN bus line, ETACS-ECU, ASC system, A/C system, or diesel fuel system may also be defective.

PROBABLE CAUSES

Malfunction of CAN bus system.
Damaged harness or connector.
Malfunction of the diesel fuel system.
Malfunction of the ASC system.
Malfunction of the A/C system.
Malfunction of fusible link SBF3.
Malfunction of fusible link SBF4.
Malfunction of radiator fan relay.
Malfunction of condenser fan relay.
Malfunction of fan control relay.
Malfunction of radiator fan motor.
Malfunction of condenser fan motor.
Malfunction of engine compartment relay box.
Malfunction of ETACS-ECU.
Malfunction of engine-ECU.

DIAGNOSIS PROCEDURE

caution

If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
Before replacing the ECU, ensure that the CAN bus lines is normal.

STEP 1. Check the CAN bus system diagnosis.

Using M.U.T.-III, perform CAN bus diagnosis (Refer to GROUP 54C - Explanation About The M.U.T-III CAN Bus Diagnostics

Q. Is the check result satisfactory?

	Go to Step 2.

	Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting, CAN Bus Diagnostic Table ). Then go to Step 24.

STEP 2. Check the diesel fuel system actuator test.

Using M.U.T.-III to check the diesel fuel system actuator test (Refer to GROUP 13D - Troubleshooting, Actuator Test Reference Table

Item 12: Fan relay 1.

Item 13: Fan relay 2.

Q. Is the check result normal?

	Go to Step 23.

	Go to Step 3.

STEP 3. Check the diesel fuel system diagnosis code.

Using M.U.T.-III, perform MPI system diagnosis code (Refer to GROUP 13D - Troubleshooting, Diagnosis Function

Q. Is any diagnosis code set?

	Repair the MPI system (Refer to GROUP 13D - Troubleshooting, Inspection Chart for Diagnosis Code ). Then go to Step 24.

	Go to Step 4.

STEP 4. Check the ASC system diagnosis code.

Using M.U.T.-III, perform ASC system diagnosis code (Refer to GROUP 35C - Troubleshooting, Diagnosis Function

Q. Is any diagnosis code set?

	Repair the ASC system (Refer to GROUP 35C - Troubleshooting, Diagnosis Code Chart ). Then go to Step 24.

	Go to Step 5.

STEP 5. Check the A/C system diagnosis code.

Using M.U.T.-III, perform A/C system diagnosis code (Refer to GROUP 55 - Troubleshooting, Diagnosis Function

Q. Is any diagnosis code set?

	Repair the A/C system (Refer to GROUP 55 - Troubleshooting, Diagnosis Code Chart ). Then go to Step 24.

	Go to Step 6.

STEP 6. Check the ETACS system diagnosis code.

Using M.U.T.-III, perform ETACS system diagnosis code (Refer to GROUP 54A - ETACS, Troubleshooting, Diagnosis Function

Q. Is any diagnosis code set?

	Repair the ETACS system (Refer to GROUP 54A - ETACS, Troubleshooting, Diagnosis Code Chart ). Then go to Step 24.

	Go to Step 7.

STEP 7. Check the radiator fan relay, the condenser fan relay, and the fan control relay.

Refer to

Q. Is the check result normal?

	Go to Step 8.

	Replace the damaged relay (Refer to ). Then go to Step 24.

STEP 8. Check the radiator fan motor and the condenser fan motor.

Refer to

Q. Is the check result normal?

	Go to Step 9.

	Replace the damaged fan motor (Refer to ). Then go to Step 24.

STEP 9. Check of short to power supply, short to earth, open circuit and harness damage in power supply line between fusible link (SBF4) and radiator fan relay connector.

Q. Is the check result normal?

	Go to Step 10.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 10. Check of short to power supply, short to earth, open circuit and harness damage in power supply line between fusible link (SBF3) and condenser fan relay connector.

Q. Is the check result normal?

	Go to Step 11.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 11. Check of short to power supply, short to earth, open circuit and harness damage in power supply line between fusible link (SBF3) and fan control relay connector.

Q. Is the check result normal?

	Go to Step 12.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 12. Check of short to power supply, short to earth, open circuit and harness damage in power supply line between radiator fan relay connector and radiator fan motor connector.

Q. Is the check result normal?

	Go to Step 13.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 13. Check of short to power supply, short to earth, open circuit and harness damage in power supply line between radiator fan motor connector and fan control relay connector.

Q. Is the check result normal?

	Go to Step 14.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 14. Check of short to power supply, short to earth, open circuit and harness damage in power supply line between condenser fan relay connector and condenser fan motor connector.

Q. Is the check result normal?

	Go to Step 15.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 15. Check of short to power supply, short to earth, open circuit and harness damage in power supply and control line between fan control relay connector and condenser fan relay connector.

Q. Is the check result normal?

	Go to Step 16.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 16. Check of short to power supply, short to earth, open circuit and harness damage in body earth line between fan control relay and body earth.

Q. Is the check result normal?

	Go to Step 17.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 17. Check of short to power supply, short to earth, open circuit and harness damage in body earth line between condenser fan motor connector and body earth.

Q. Is the check result normal?

	Go to Step 18.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 18. Check of short to power supply, short to earth, open circuit and harness damage in F/LO line between radiator fan relay connector and ETACS-ECU connector.

Q. Is the check result normal?

	Go to Step 19.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 19. Check of short to power supply, short to earth, open circuit and harness damage in F/HI line between condenser fan relay connector and ETACS-ECU connector.

Q. Is the check result normal?

	Go to Step 20.

	Repair the connector(s) or wiring harness. Then go to Step 24.

STEP 20. Check the fusible link SBF3 and SBF4.

Q. Is the check result normal?

	Go to Step 21.

	Replace the damaged fusible link. Then go to Step 24.

STEP 21. Check the ETACS system diagnosis code.

Using M.U.T.-III, perform ETACS system diagnosis code (Refer to GROUP 54A - ETACS, Troubleshooting, Diagnosis Function

Q. Is any diagnosis code set?

	Replace the ETACS-ECU (Refer to GROUP 54A - ETACS, ETACS-ECU ). Then go to Step 24.

	Go to Step 22.

STEP 22. Check the diesel fuel system actuator test.

Using M.U.T.-III, check the MPI system actuator test (Refer to GROUP 13D - Troubleshooting, Actuator Test Reference Table

Item 12: Fan relay 1.

Item 13: Fan relay 2.

Q. Is the check result normal?

	Go to Step 23.

	Replace the engine-ECU (Refer to GROUP 13D - Engine-ECU ). Then go to Step 24.

STEP 23. Check the symptoms.

Q. Does the radiator fan and condenser fan operate normal?

	It can be assumed that this malfunction is intermittent (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunction ).

	Replace the engine-ECU (Refer to GROUP 13D - Engine-ECU ). Then go to Step 24.

STEP 24. Check the symptoms.

Q. Does the radiator fan and condenser fan operate normal?

	The procedure is complete.

	Return to Step 1.