Audio Communication Line Circuit Troubleshooting
  1. Disconnect climate control unit connector A (28P) and the center display unit 12P connector.
  1. Check for continuity between the following terminals of heater control unit connector A (28P) and the center display unit 12P connector.
    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 heater control unit connector A (28P) and the center display unit 12P connector.■