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

Normal Operation
The audio unit communicates with the scan tool through the medium speed controller area network (MS-CAN). Circuits VDB06 (GY/OG) (HS-CAN +) and VDB07 (VT/OG) (HS-CAN -) provide the network connection to the audio unit. The audio unit shares the MS-CAN network with the electronic automatic temperature control (EATC) or electronic manual temperature control (EMTC) module, the smart junction box (SJB), the driver seat module (DSM), the digital versatile disc (DVD) player, the satellite radio receiver, the power liftgate module and the instrument cluster. Voltage for the audio unit is provided by circuit SPB39 (WH/RD) and circuit GD103 (BK/BU) provides ground.

This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Audio unit

I1-I2:

I2-I3:

I4: