Diesel Data: Automotive Repair

Audio Communication Line Circuit Troubleshooting




Audio Communication Line Circuit Troubleshooting

With navigation

1. Turn the ignition switch to LOCK (0).

2. Disconnect climate control unit connector B (20P) and audio unit connector D (20P).

3. Check for continuity between the following terminals of climate control unit connector B (20P) and audio unit connector D (20P).









Is there continuity?

YES -

Go to step 4.

NO -

Repair an open in the wire between the climate control unit and the audio unit.�

4. Check for continuity between body ground and climate control unit connector B (20P) terminals No. 1 and No. 8 individually.





Is there continuity?

YES -

Repair a short to body ground in the wire(s) between the climate control unit and the audio unit.�

NO -

Go to step 5.

5. Reconnect climate control unit connector B (20P).

6. Connect audio unit connector D (20P) terminals No. 6 and No. 7 with a jumper wire.






7. Turn the ignition switch to ON (II).

8. Press and hold the DEF button and FAN ON/OFF button.

Is the DEF button LED blinking?

YES -

Audio unit is faulty, replace the audio unit Audio Unit Removal/Installation.�

NO -

Climate control unit is faulty, replace the climate control unit Climate Control Unit Removal/Installation.�

Without navigation

9. Turn the ignition switch to LOCK (0).

10. Disconnect climate control unit connector B (20P) and audio unit connector D (20P).

11. Check for continuity between the following terminals of climate control unit connector B (20P) and audio unit connector D (20P).









Is there continuity?

YES -

Go to step 4.

NO -

Repair an open in the wire between the climate control unit and the audio unit.�

12. Check for continuity between body ground and climate control unit connector B (20P) terminals No. 1 and No. 8 individually.





Is there continuity?

YES -

Repair a short to body ground in the wire(s) between the climate control unit and the audio unit.�

NO -

Go to step 5.

13. Reconnect climate control unit connector B (20P).

14. Connect audio unit connector D (20P) terminals No. 11 and No. 12 with a jumper wire.






15. Turn the ignition switch to ON (II).

16. Press and hold the DEF button and FAN ON/OFF button.

Is the DEF button LED blinking?

YES -

Audio unit is faulty, replace the audio unit Audio Unit Removal/Installation.�

NO -

Climate control unit is faulty, replace the climate control unit Climate Control Unit Removal/Installation.�