Inspection Procedure 4: The audio does not operate normally by operating the audio control unit of the centre panel unit.















COMMENTS ON TROUBLE SYMPTOM


When the audio does not operate normally by operating the audio control unit of the centre panel unit, the audio unit, centre panel unit, or the power supply circuit system of centre panel unit may be faulty.

PROBABLE CAUSES



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

DIAGNOSIS PROCEDURE


STEP 1. Connector check: C-106 centre panel unit connector


Q. Is the check result normal?

Go to Step 2.
Repair the defective connector.

STEP 2. Resistance measurement at C-106 centre panel unit connector


(1)Disconnect the connector, and measure at the wiring harness-side connector.
(2)Check the continuity between C-106 centre panel unit connector terminal No.9 and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 4.
Go to Step 3.

STEP 3. Check the wiring harness between C-106 centre panel unit connector terminal No.9 and body earth.



  • Check the earth wires for open circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Repair the wiring harness.

STEP 4. Voltage measurement at C-106 centre panel unit connector.


(1)Disconnect the connector, and measure at the wiring harness-side connector.
(2)Measure the voltage between C-106 centre panel unit connector terminal No.7 and body earth.
OK: Battery voltage

Q. Is the check result normal?

Go to Step 6.
Go to Step 5.

STEP 5. Check the wiring harness between C-106 centre panel unit connector terminal No.7 and fusible link No.34.



  • Check the power supply line for open circuit and short circuit.
note Prior to the wiring harness inspection, check ETACS-ECU connectors C-307 and C-317, and repair if necessary.

Q. Is the check result normal?

Go to Step 8.
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 defective connector.

STEP 7. Check the wiring harness between C-16 audio unit connector terminal No.8, 18 and C-106 centre panel unit connector terminal No.1, 2.



  • 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 works normally.

Q. Is the check result normal?

Replace the centre panel unit.
Replace the audio unit.