Inspection Procedure 8: The rear window defogger does not work.






















CIRCUIT OPERATION
If the rear window defogger does not operate when the rear window defogger switch is turned on, the rear window defogger relay system may be defective.

TROUBLESHOOTING HINTS

  • Malfunction of the control panel sub assembly
  • Malfunction of the A/C-ECU
  • Malfunction of the rear window defogger relay
  • Damaged the wiring harness or connectors
  • Malfunction of the rear window defogger

DIAGNOSIS PROCEDURE

STEP 1. Check the A/C and outside/inside air selection damper control motor operation.

Q. Do the A/C and outside/inside air selection damper control motor work normally?
Go to Step 2.
Refer to Inspection procedure 14 "Malfunction of the A/C-ECU power supply system ."

STEP 2. Connector check: D-08 A/C-ECU connector and G-15 rear window defogger


Q. Is the check result normal?
Go to Step 3.
Repair the connector.

STEP 3. Voltage measurement at G-15 rear window defogger connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Turn the ignition switch to the "ON" position.
(3)Disconnect A/C-ECU connector D-08 and earth terminal 15.
(4)Measure the voltage between terminal 1 and body earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 12.
Go to Step 4.

STEP 4. Connector check: D-407 rear window defogger relay connector


Q. Is the check result normal?
Go to Step 5.
Repair the connector.

STEP 5. Check the rear window defogger relay continuity.
Refer to .

Q. Is the rear window defogger relay in good condition?
Go to Step 6.
Replace the rear window defogger relay.

STEP 6. Voltage measurement at D-407 rear window defogger relay connector.


(1)Remove the relay, and measure at the junction block side.
(2)Measure the voltage between terminal 5 and body earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 8.
Go to Step 7.

STEP 7. Check the wiring harness between D-405 rear window defogger relay connector terminal No.5 and the fusible link (2).
note Prior to the wiring harness inspection, check intermediate connectors D-240, and junction block connector D-404, and repair if necessary.

  • Check the rear window defogger relay power supply line for open and short 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 8. Voltage measurement at D-407 rear window defogger relay connector.


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

Q. Is the check result normal?
Go to Step 10.
Go to Step 9.

STEP 9. Check the wiring harness between D-403 rear window defogger relay connector No.1 and ignition switch (IG2).
note Prior to the wiring harness inspection, check junction block connector D-403, and repair if necessary.

  • Check the rear window defogger 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 10. Check the wiring harness between D-407 rear window defogger relay connector No.3 and D-08 A/C-ECU connector No.15.
note Prior to the wiring harness inspection, check junction block connector C-405, and repair if necessary.

  • Check the rear window defogger power supply line for open circuit.

Q. Is the check result normal?
Go to Step 11.
Repair the wiring harness.

STEP 11. Check the wiring harness between D-407 rear window defogger relay connector No.4 and G-15 rear window defogger connector No.1.
note Prior to the wiring harness inspection, check junction block connector D-422 <RHD> or D-409 <LHD> and intermediate connector D-220 <LHD> E-105, and repair if necessary.

  • Check the rear window defogger relay line for open and short 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 12. Connector check: G-04 rear window defogger connector

Q. Is the check result normal?
Go to Step 13.
Repair the connector.

STEP 13. Resistance measurement at G-04 rear window defogger connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Continuity between terminal 1 and body earth.
OK: 2Ω or less

Q. Is the check result normal?
Go to Step 15.
Go to Step 14.

STEP 14. Check the wiring harness between G-04 rear window defogger connector terminal No.1 and earth.

  • Check the rear window defogger earth line for open and short 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 or replace the wiring harness.

STEP 15. Check the rear window defogger.
Refer to GROUP 54A, Rear Window rear window defogger Switch Inspection .

Q. Does the rear window defogger work normally?

Go to Step 16.
Repair the rear window defogger.

STEP 16. Replace the control panel sub assembly and check the trouble symptom
Check that the rear window rear window defogger operates normally.

Q. Is the check result normal?
This diagnosis is complete.
Replace the A/C-ECU.