Audio Communication Line Circuit Troubleshooting

Audio Communication Line Circuit Troubleshooting

1. Disconnect climate control unit connector A (28P) and the audio-navigation switch panel 24P connector (with navigation) or audio-HVAC display unit 12P connector (without navigation).

2. Check for continuity between the following terminals of climate control unit connector A (28P) and the audio-navigation switch panel 24P connector or audio-HVAC display unit 12P connector.









Is there continuity?
YES - Go to step 3.

NO - Repair an open in the wire between climate control unit connector A (28P) and the audio-navigation switch panel 24P connector or audio-HVAC display unit 12P connector.










3. 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 connector A (28P) and the audio-navigation switch panel 24P connector or audio-HVAC display unit 12P connector.

NO - Go to step 4.






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

5. With navigation: Connect the audio-navigation switch panel 24P connector terminals No. 7 and No. 19 with a jumper wire.
Without navigation: Connect the audio-HVAC display unit 12P connector terminals No. 7 and No. 8 with a jumper wire.

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

7. Press and hold the front DEF button and OFF button.

Is the front DEF button LED blinking?
YES - The audio-navigation switch panel or audio-HVAC display unit is faulty, replace the audio-navigation switch panel Audio-Navigation Switch Panel Removal/Installation or audio-HVAC display unit. Audio-HVAC Display Unit Removal/Installation (With Premium Audio System)

NO - The climate control unit is faulty, replace the climate control unit. Climate Control Unit Removal/Installation