Inspection Procedure 4: The Audio does not Operate Normally by Operating the Audio Control Unit of the Centre Panel Unit.


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










COMMENTS ON TROUBLE SYMPTOM
When the audio does not operate normally by operating the audio control unit of the centre panel unit, the radio and CD player, centre panel unit, or the power supply circuit system of centre panel unit may be faulty.

PROBABLE CAUSES

  • Malfunction of radio and CD player
  • Malfunction of centre panel unit
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-10 centre panel unit connector

Q. Is the check result normal?
Go to Step 2.
Repair the defective connector.

STEP 2. Resistance measurement at C-10 centre panel unit connector
(1)Disconnect the connector, and measure at the wiring harness-side connector.
(2)Check the continuity between C-10 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-10 centre panel unit connector terminal No.9 and body earth.

  • Check the earth wire 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-10 centre panel unit connector.
(1)Disconnect the connector, and measure at the wiring harness-side connector.
(2)Measure the voltage between C-10 centre panel unit connector terminal No.7 and body earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 6.
Go to Step 5.

STEP 5. Check the wiring harness between C-10 centre panel unit connector terminal No.7 and fusible link No.36 <PETROL> or No.38 <DIESEL>

  • Check the power supply line for open circuit or 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-105 radio and CD player connector

Q. Is the check result normal?
Go to Step 7.
Repair the defective connector.

STEP 7. Check the wiring harness between C-105 radio and CD player connector terminal No.8, 18 and C-10 centre panel unit connector terminal No.1, 2.

  • Check the communication lines for open circuit or short 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 radio and CD player.