Diesel Data: Automotive Repair

Audio Communication Line Circuit Troubleshooting (With Climate Control, Without Navigation)




Audio Communication Line Circuit Troubleshooting

Without Navigation System

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

2. Disconnect climate control unit connector A (28P) and the audio-HVAC display unit 12P connector.

3. Check for continuity between the following terminals of climate control unit connector A (28P) and the audio-HVAC display unit 12P connector.









Is there continuity?

YES -

Go to step 4.

NO -

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

4. Check for continuity between body ground and climate control unit connector A (28P) terminals No. 19 and No. 20 individually.





Is there continuity?

YES -

Repair a short to body ground in the wire between climate control unit and the audio-HVAC display unit.�

NO -

Go to step 5.

5. Reconnect climate control unit connector A (28P).

6. Connect audio-HVAC display unit 12P connector terminals No. 7 and No. 8 with a jumper wire.





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

8. Press and hold the windshield defroster button and the OFF button ('08-09 models) or the ON/OFF button ('10-11 models).

9. Check the windshield defroster button LED.

Is the LED blinking?

YES -

Audio-HVAC display unit is faulty, replace the audio-HVAC display unit Audio-HVAC Display Unit Removal/Installation.�

NO -

Climate control unit is faulty, replace the climate control unit Climate Control Unit Removal/Installation (Without Navigation).�