Inspection Procedure 20: Condenser Fan Relay System




OPERATION



  • The A/C condenser fan relay is controlled by turning on and off the power transistor in the engine-ECU.
  • In response to the A/C switch signal, A/C load signal, vehicle speed and engine coolant temperature, the engine-ECU controls the condenser fan relay.

PROBABLE CAUSES



  • Failed condenser fan relay
  • Failed condenser fan motor
  • Damaged harness (Open or short circuit between engine-ECU and condenser fan relay, Open circuit between condenser fan motor and earth, condenser fan relay and J/B, condenser fan relay and relay box, and open circuit between condenser fan relay and condenser fan motor)
  • Damaged connector (condenser fan relay connector, condenser fan motor connector, Engine-ECU connector)
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item 26: A/C load signal <Automatic A/C>

Q. Is the check result normal?
Go to Step 2 .
Check A/C system (Refer to GROUP 55B - Troubleshooting - Trouble Symptom Chart ).

STEP 2. Check at C-105 engine-ECU connector.


  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Short-circuit terminal No. 39 to earth.
OK: Condenser fan motor rotates.

Q. Is the check result normal?

Go to Step 3 .

Check condenser fan system (Refer to GROUP 55A - Troubleshooting - Trouble Symptom Chart ).

STEP 3. Connector check: C-105 engine-ECU connector.

Q. Is the check result normal?

Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).

Repair or replace.