Climate Control-Audio Communication Line Circuit Troubleshooting
  1. Disconnect climate control unit connector A (28P) and the audio/navigation switch panel 24P connector (with navigation) or center display unit 12P connector (without navigation).
  1. Check for continuity between the following terminals of climate control unit connector A (28P) and the audio/navigation switch panel 24P connector or center display unit 12P connector.
    With navigation
    28P:
    24P:
    No. 19
    No. 7
    No. 20
    No. 19
    28P:
    12P:
    No. 19
    No. 7
    No. 20
    No. 8


Is there continuity?
YES -
Go to Step 3 .
NO -
Repair open in the wire between climate control unit connector A (28P) and the audio/navigation switch panel 24P connector or center display unit 12P connector.■
  1. Check for continuity between body ground and climate control unit connector A (28P) No. 19 and No. 20 terminals individually.
Is there continuity?
YES -
Repair short to body ground in the wire between climate control unit connector A (28P) and the audio/navigation switch panel 24P connector or center display unit 12P connector.■
NO -
Go to Step 4 .
  1. Reconnect climate control unit connector A (28P).
  1. With navigation: Connect the audio/navigation switch panel 24P connector No. 7 and No. 19 terminals with a jumper wire. Without navigation: Connect the center display unit 12P connector No. 7 and No. 8 terminals with a jumper wire.
  1. Turn the ignition switch to ON (II).
  1. Press and hold the DEF button and OFF button.
Is the DEF button LED blinking?
YES -
Audio/navigation switch panel or center display unit is faulty, replace the audio/navigation switch panel or center display unit. ■
NO -
Climate control unit is faulty, replace the climate control unit. ■