Inspection Procedure 3
Inspection Procedure 3: Radiator Fan and Condenser Fan do not Operate.
CIRCUIT OPERATION
- Based on the signal from the engine coolant temperature sensor and the signal from the vehicle speed sensor[ M/T] or the secondary pulley speed sensor signal (vehicle speed signal) from the transaxle control module (TCM)[ CVT], and the A/C switch signal from the A/C-ECU, the engine control module (ECM) 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 ECM, 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, CVT system, A/C system, or MFI system may also be defective.
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CASE:)
- Malfunction of CAN bus system.
- Damaged harness or connector.
- Malfunction of the MFI system.
- Malfunction of the CVT system.
- Malfunction of the A/C system.
- Malfunction of fusible link No. 28.
- Malfunction of fusible link No. 29.
- 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 ECM.
DIAGNOSTIC PROCEDURE
CAUTION:
If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines CAN Bus Line Diagnostics Flow.)
STEP 1. Using scan tool MB991958, check the CAN bus line diagnostics.
Use scan tool to diagnose the CAN bus line CAN Bus Line Diagnostics Flow).
Q. Is the check result satisfactory?
YES Go to Step 2.
NO Repair the CAN bus lines CAN Bus Diagnostics Chart). Then go to Step 23.
STEP 2. Using scan tool MB991958, check the MFI system actuator test.
Using scan tool to check the MFI system actuator test Scan Tool Testing and Procedures).
- Item 14: Cooling fan
Actuator Test Reference Table)
Q. Is the check result normal?
YES Go to Step 22.
NO Go to Step 3.
STEP 3. Using scan tool MB991958, read the MFI system DTC.
Using scan tool to read the MFI system DTC Reading and Clearing Diagnostic Trouble Codes).
Q. Is any DTC set?
YES Repair the MFI system Multiport Fuel Injection (MFI)). Then go to Step 23.
NO Go to Step 5[M/T].
NO Go to Step 4[CVT].
STEP 4. Using scan tool MB991958, read the CVT system DTC [CVT].
Using scan tool to read the CVT system DTC Reading and Clearing Diagnostic Trouble Codes).
Q. Is any DTC set?
YES Repair the CVT system Continuously Variable Transaxle (CVT)). Then go to Step 23.
NO Go to Step 5.
STEP 5. Using scan tool MB991958, read the A/C system DTC.
Using scan tool to read the A/C system DTC Reading and Clearing Diagnostic Trouble Codes) [vehicles with manual A/C]
or Reading and Clearing Diagnostic Trouble Codes) [vehicles with automatic A/C].
Q. Is any DTC set?
YES Repair the A/C system Manual Air Conditioning) [vehicles with manual A/C]
or Automatic Air Conditioning) [vehicles with automatic A/C]. Then go to Step 23.
NO Go to Step 6.
STEP 6. Using scan tool MB991958, read the ETACS system DTC.
Using scan tool to read the ETACS system DTC Reading and Clearing Diagnostic Trouble Codes).
Q. Is any DTC set?
YES Repair the ETACS system Electronic Time and Alarm Control System (ETACS)). Then go to Step 23.
NO Go to Step 7.
STEP 7. Measure the terminal voltage at ETACS-ECU connector C-410.
(1)Disconnect the ETACS-ECU connector C-410 and measure at the harness connector side.
(2)Turn the ignition switch to the "ON" position.
(3)Measure the terminal voltage between ETACS-ECU connector C-410 terminal number 2 and body ground, and between ETACS-ECU connector C-410 terminal number 8 and body ground.
OK: Battery positive voltage.
Q. Is the check result normal?
YES Go to Step 13.
NO Go to Step 8.
STEP 8. Check the condenser fan relay connector A-30X, radiator fan relay connector A-33X, fan control relay connector A-35X, and ETACS-ECU connector C-410, for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Harness Connector Inspection.
Q. Are the connectors and terminals in good condition?
YES Go to Step 9.
NO Repair or replace the damaged connectors or replace the relay box. Then go to Step 23.
STEP 9. Check the harness wire between fusible link number 28 and condenser fan relay connector A-30X terminal number 1, between fusible link number 28 and fan control relay connector A-35X terminal number 1, and between fusible link number 29 and radiator fan relay connector A-33X terminal number 3, for damage.
- Check harness wire for open/short circuit and damage.
Q. Are the harness wires in good condition?
YES Go to Step 10.
NO Repair or replace the damaged harness wire or replace the relay box. Then go to Step 23.
STEP 10. Check the harness wire between condenser fan relay connector A-30X terminal number 2 and ETACS-ECU connector C-410 terminal number 8, between radiator fan relay connector A-33X terminal number 1 and ETACS-ECU connector C-410 terminal number 2, and between fan control relay connector A-35X terminal number 3 and ETACS-ECU connector C-410 terminal number 8, for damage.
- Check harness wire for open/short circuit and damage.
Q. Are the harness wires in good condition?
YES Go to Step 11.
NO Repair or replace the damaged harness wire. Then go to Step 23.
STEP 11. Check the radiator fan relay, the condenser fan relay and the fan control relay.
Refer to Testing and Inspection.
Q. Is the relay in good condition?
YES Go to Step 12.
NO Replace the damaged relay. Then go to Step 23.
STEP 12. Check the fusible link number 28 and fusible link number 29.
Q. Is the fusible link in good condition?
YES Go to Step 20.
NO Replace the damaged fusible link. Then go to Step 23.
STEP 13. Check the condenser fan relay connector A-30X, radiator fan relay connector A-33X, fan control relay connector A-35X, radiator fan motor connector A-50, and condenser fan motor connector A-54, for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Harness Connector Inspection.
Q. Are the connectors and terminals in good condition?
YES Go to Step 14.
NO Repair or replace the damaged connectors or replace the relay box. Then go to Step 23.
STEP 14. Check the harness wire between fusible link number 28 and condenser fan relay connector A-30X terminal number 4, and between fusible link number 29 and radiator fan relay connector A-33X terminal number 4, for damage.
- Check harness wire for open/short circuit and damage.
Q. Are the harness wires in good condition?
YES Go to Step 15.
NO Repair or replace the damaged harness wire or replace the relay box. Then go to Step 23.
STEP 15. Check the harness wire between condenser fan relay connector A-30X terminal number 3 and condenser fan motor connector A-54 terminal number 1, and between radiator fan relay connector A-33X terminal number 2 and radiator fan motor connector A-50 terminal number 1, for damage.
- Check harness wire for open/short circuit and damage.
Q. Are the harness wires in good condition?
YES Go to Step 16.
NO Repair or replace the damaged harness wire. Then go to Step 23.
STEP 16. Check the harness wire between radiator fan motor connector A-50 terminal number 2 and fan control relay connector A-35X terminal number 5, and between condenser fan motor connector A-54 terminal number 2 and body ground, for damage.
- Check harness wire for open/short circuit and damage.
Q. Are the harness wires in good condition?
YES Go to Step 17.
NO Repair or replace the damaged harness wire. Then go to Step 23.
STEP 17. Check the harness wire between fan control relay connector A-35X terminal number 2 and condenser fan motor connector A-54 terminal number 1, and between fan control relay connector A-35X terminal number 4 and body ground, for damage.
- Check harness wire for open/short circuit and damage.
Q. Are the harness wires in good condition?
YES Go to Step 18.
NO Repair or replace the damaged harness wire. Then go to Step 23.
STEP 18. Check the radiator fan relay, the condenser fan relay and the fan control relay.
Refer to Testing and Inspection.
Q. Is the relay in good condition?
YES Go to Step 19.
NO Replace the damaged relay. Then go to Step 23.
STEP 19. Check the radiator fan motor and the condenser fan motor.
Refer to Testing and Inspection.
Q. Is the fan motor in good condition?
YES Go to Step 20.
NO Replace the damaged fan motor (Refer to Service and Repair). Then go to Step 23.
STEP 20. Using scan tool MB991958, read the ETACS system DTC.
Using scan tool to read the ETACS system DTC Reading and Clearing Diagnostic Trouble Codes).
Q. Is any DTC set?
YES Replace the ETACS-ECU Electronic Time and Alarm Control System (ETACS)-ECU Removal and Installation). Then go to Step 23.
NO Go to Step 21.
STEP 21. Using scan tool MB991958, check the MFI system actuator test.
Using scan tool to check the MFI system actuator test Scan Tool Testing and Procedures).
- Item 14: Cooling fan
Actuator Test Reference Table)
Q. Is the check result normal?
YES Go to Step 22.
NO Replace the ECM [ Removal and Replacement]. Then go to Step 23.
STEP 22. Check the symptom.
Q. Does the radiator fan and condenser fan operate normal?
YES An intermittent malfunction is suspected How to Cope With Intermittent Malfunctions).
NO Replace the ECM [ Removal and Replacement]. Then go to Step 23.
STEP 23. Check the symptom.
Q. Does the radiator fan and condenser fan operate normal?
YES The procedure is complete.
NO Return to Step 1.