Test A: The Audio Unit Is Inoperative

PINPOINT TEST A: THE AUDIO UNIT IS INOPERATIVE

A1-A2:

A3-A6:

A6-A9:

A9-A11:

A12-A14:

A14-A16:

A17-A19:

A20-A22:

Normal Operation
The integrated control panel (ICP) acts as the user-interface between the driver and the rear control unit (RCU) (also referred to as the audio unit), which is located in the trunk. The ICP and the audio unit communicate with each other via circuit 832 (LB/PK) and circuit 833 (TN), using the audio corporate protocol (ACP). Circuit 1068 (LG/BK) is used to transmit a "wake-up call" when the system is turned on. The speaker signals are sent from the ICP to the audio unit, which amplifies the signals and transmits them to the speakers.

Possible Causes
- Fuse(s)
- Circuit 372 (BN/OG) short to ground or short to voltage
- Circuit 385 (WH/RD) open
- Circuit 640 (RD/YE) open
- Circuit 1002 (BK/PK) open
- Circuit 57 (BK) open
- Circuit 651 (BK/YE) open
- Circuit 655 (RD/OG) open
- Circuit 720 (RD/YE) open
- Circuit 694 (BK/LG) open
- Circuit 1068 (LG/BK) open, short to ground or short to voltage
- Circuit 832 (LB/PK) open, short to ground or short to voltage
- Circuit 833 (TN) open, short to ground or short to voltage
- RCU
- Compact disc (CD) changer
- ICP