Inspection Procedure 4

Inspection Procedure 4: The sound of external input are not played.

CAUTION: Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.

Audio Adapter Communication Circuit (Part 1):

Audio Adapter Communication Circuit (Part 2):

COMMENTS ON TROUBLE SYMPTOM
If the external input sound is not output, the radio and CD player or CD changer, audio communication line of radio and CD player or CD changer, or audio adapter may have a problem.

PROBABLE CAUSES
- The audio adapter may be defective.
- The radio and CD player or CD changer may be defective.
- Damaged harness wires and connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Operation check of the radio and CD player or CD changer

Check if the radio and CD player or CD changer operates normally and outputs sound.

Q: Is the check result normal?

YES : Go to Step 2.

NO : Troubleshoot the radio and CD player. Trouble Symptom Chart

STEP 2. Check the external sound input mode.

Check if the external sound input mode of the radio and CD player or CD changer is set.

Q: Is the check result normal?

YES : Go to Step 3.

NO : Set the external sound input mode.

STEP 3. Check the audio adapter.

Check if the audio adapter is normal.

Q: Is the check result normal?

YES : Go to step 4.

NO : Replace the Audio adapter.

STEP 4. Check audio adapter connector C-117 and radio and CD player or CD changer connector C-14 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are audio adapter connector C-117 and radio and CD player or CD changer connector C-14 in good condition?

YES : Go to step 5.

NO : Repair or replace the damaged component(s) (Refer to general (electrical), Harness Connector Inspection).

STEP 5. Check the wiring harness between audio adapter connector C-117 (terminal 5, 4, 6) and radio and CD player or CD changer connector C-14 (terminal 14, 13, 4).

- Check the communication lines for open circuit and short circuit.

NOTE: Also check intermediate connectors D-123 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-123 is damaged, repair or replace the connector as described in general (electrical), Harness Connector Inspection.

Q: Is the wiring harness between audio adapter connector C-117 (terminal 5, 4, 6) and radio and CD player or CD changer connector C-14 (terminal 14, 13, 4) in good condition?

YES : Replace the audio adapter, and go to Step 6.

NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

STEP 6. Retest the system.

Check that the external input is normal.

Q: Is the check result normal?

YES : The trouble can be an intermittent malfunction (Refer to general (Body and Chassis) How to use Troubleshooting/inspection Service Points How to Cope with Intermittent Malfunction).

NO : Replace the radio and CD player or CD changer.