Test I: The Audio Unit Does Not Respond To The Scan Tool

PINPOINT TEST I: THE AUDIO UNIT DOES NOT RESPOND TO THE SCAN TOOL

I1-I3:

I3-I4:

Normal Operation
The audio unit communicates with the scan tool through the medium speed controller area network (MS-CAN). Circuits 2180 (WH/BK) (MS-CAN +) and 2181 (BK/YE) (MS-CAN -) provide the network connection to the audio unit. The audio unit shares the MS-CAN network with the smart junction box (SJB), the driver seat module (DSM), the electronic automatic temperature control (EATC) module, the digital versatile disc (DVD) player, the satellite radio receiver, and the instrument cluster. Voltage for the audio unit is provided by circuits 1006 (BK/PK) and 1111 (VT). Circuit 1204 (BK/OG) provides ground.

Possible Causes
- Fuse
- Circuit 1006 (BK/PK) open
- Circuit 1111 (VT) open
- Circuit 1204 (BK/OG) open
- Circuit 2180 (WH/BK) open (MS-CAN +)
- Circuit 2181 (BK/YE) open (MS-CAN -)
- Audio unit