Inspection Procedure 26

INSPECTION PROCEDURE 26: Fans (radiator fan, A/C condenser fan) Are Inoperative






COMMENT
- The fan control relay is controlled by the power transistor inside the PCM turning "ON" and "OFF".

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Malfunction of the fan control relay.
- Malfunction of the condenser fan relay.
- Malfunction of the radiator fan relay.
- Malfunction of the condenser fan motor.
- Malfunction of the radiator fan motor.
- Improper connector contact, open or shorted harness wire.
- PCM failed.

DIAGNOSIS

Required Special Tools:
- MB991958: Scan tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A

STEP 1. Check harness connector B-19 at PCM for damage.






Q: Is the harness connector in good condition?

YES : Go to Step 2.

NO : Repair or replace it. Then confirm that the malfunction symptom is eliminated.

STEP 2. Check the fan condition.




1. Disconnect the B-19 at PCM connector.
2. Turn the ignition switch to the "ON" position.
3. Check the fan condition.
- When the terminal No.10 is grounded by the jumper cable, the radiator and condenser fans should run.
- When the terminal No.10 is grounded first and then both of the terminal No.10 and No.5 are grounded next, check that the rotation speed of fan is higher than the rotation speed when the terminal No.10 is grounded.

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the fan condition normal?

YES : Go to Step 3.

NO : Refer to Symptom Chart. Symptom Chart

STEP 3. Using scan tool MB991958, check data list item 6: Engine Coolant Temperature Sensor.






CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Start the engine and run at idle.
3. Check the following items in the data list. Refer to Data List Reference Table. Datal List Reference Table
a. Item 6: Engine Coolant Temperature Sensor

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the sensor operating properly?

YES : Go to Step 4.

NO : Repair and replace. Then confirm that the malfunction symptom is eliminated.

STEP 4. Check the cooling system.

Refer to Symptom Chart. Symptom Chart

Q: Is the cooling system normal?

YES : Replace the PCM. When the PCM is replaced, register the encrypted code.

NO : Replace it. Then confirm that the malfunction symptom is eliminated.