Inspection Procedure 13: Rear air outlet vent cannot be changed <Dual A/C>


















COMMENTS ON TROUBLE SYMPTOM


When the rear outlet switching cannot be made, the circuit between the rear mode selection damper control motor and A/C-ECU may have a failure.

PROBABLE CAUSES



  • Malfunction of the rear mode selection damper control motor.
  • Malfunction of the automatic A/C control panel (A/C-ECU)
  • Damaged the wiring harness or connectors

DIAGNOSIS PROCEDURE


STEP 1. Connector check: E-34-3 rear mode selection damper control motor connector


Q. Is the check result normal?

Go to Step 2.
Repair the connector.

STEP 2. Voltage measurement at E-34-3 rear mode selection damper control motor connector.


(1)Remove the relay, and measure at the junction block side.
(2)Turn the ignition switch to the ON position.
(3)Voltage between terminal 2 and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 4.
Go to Step 3.

STEP 3. Check the wiring harness between E-34-3 rear mode selection damper control motor connector terminal No.2 and the ignition switch (IG2).


note Prior to the wiring harness inspection, check junction block connector D-401, D-403, joint connector D-42, intermediate connector D-220 <RHD>, D-222<LHD> and rear blower assembly connector E-34, and repair if necessary.

  • Check the rear mode selection damper control motor power supply line for open circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the wiring harness.

STEP 4. Resistance measurement at the E-34-3 rear mode selection damper control motor connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Continuity between terminal 1 and body earth
OK: Continuity (Less than 2 ohms)

Q. Is the check result normal?

Go to Step 6.
Go to Step 5.

STEP 5. Check the wiring harness between E-34-3 rear mode selection damper control motor connector terminal No.1 and body earth.


note Prior to the wiring harness inspection, check rear blower assembly connector E-34, and repair if necessary.

  • Check the mode selection damper control motor earth line for open circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the wiring harness.

STEP 6. Connector check: D-07 A/C-ECU connector


Q. Is the check result normal?

Go to Step 7.
Repair the connector.

STEP 7. Check the wiring harness between E-34-3 rear mode selection damper control motor connector (terminal 6, 4 and 3) and D-07 A/C-ECU connector (terminal 50, 49 and 48).


note Prior to the wiring harness inspection, check rear blower assembly connector E-34 and intermediate connector D-219, and repair if necessary.

  • Check the A/C-ECU input line for open circuit.

Q. Is the check result normal?

Go to Step 8.
Repair the wiring harness.

STEP 8. Replace the rear mode selection damper control motor and recheck the trouble symptom


Check that the rear mode selection damper control motor operates normally.

Q. Is the check result normal?

This diagnosis is complete.
Replace the A/C-ECU.