Inspection Procedure 5: Audio illuminations does not work normally.



caution Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.








OPERATION



  • When the position lamp is illuminated, the audio illumination is switched to the nighttime illumination.
  • When the brightness is adjusted using the combination meter rheostat switch, the audio illumination brightness is also adjusted.

COMMENTS ON TROUBLE SYMPTOM




PROBABLE CAUSES



  • Malfunction of combination meter
  • Malfunctions of centre panel unit
  • Malfunctions of audio unit
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE


STEP 1. Operation check of the centre panel unit


Operate the audio control switch of the centre panel unit, and check if the audio operates normally.

Q. Is the check result normal?

Go to Step 2.
Refer to Inspection Procedure 4 "The audio does not operate normally by operating the audio control unit of the centre panel unit." .

STEP 2. Check the combination meter.


Check whether the combination meter works normally.

Q. Is the check result normal?

Go to Step 3.
Diagnose the combination meter (Refer to ).

STEP 3. M.U.T.-III other system diagnosis code


Check if diagnosis code is set to the combination meter.

Q. Is the diagnosis code set?

Diagnose the combination meter (Refer to ).
Go to Step 4.

STEP 4. Connector check: C-07 combination meter connector, C-106 centre panel unit connector


Q. Is the check result normal?

Go to Step 5.
Repair the connector concerned.

STEP 5. Check the wiring harness between C-07 combination meter connector terminal No.23, 22 and C-106 centre panel unit connector terminal No.16, 10.


note Prior to the wiring harness inspection, check A/C control panel connector C-120, and repair if necessary.

  • Check the communication line for open circuit.

Q. Is the check result normal?

Go to Step 6.
Repair the wiring harness.

STEP 6. Connector check: C-16 audio unit connector


Q. Is the check result normal?

Go to Step 7.
Repair the connector concerned.

STEP 7. Check the wiring harness between C-16 audio unit connector terminal No.9 and C-106 centre panel unit connector terminal No.4.



  • Check the communication line for open circuit.

Q. Is the check result normal?

Go to Step 8.
Repair the wiring harness.

STEP 8. Replace the centre panel unit temporarily, and check the trouble symptom.


Replace the centre panel unit temporarily, and check that the audio illumination works normally.

Q. Is the check result normal?

Replace the centre panel unit.
Replace the audio unit.