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Pinpoint Test 9: The Audio Unit Does Not Respond to the Scan Tool

PINPOINT TEST 9: 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 (GY/O) (MS-CAN +) and (V/O) (MS-CAN -) provide the network connection to the audio unit. The audio unit shares the MS-CAN network with the instrument cluster, electronic manual temperature control (EMTC) module, smart junction box (SJB), satellite radio receiver, front control interface module (FCIM) and front display interface module (FDIM). Voltage for the audio unit is provided by circuit (W/R). Ground is provided by circuit (B/GY).

Possible Causes
- Fuse
- Wiring, terminals or connectors
- Audio unit

Diagnostic Procedure

CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

Step 1-Step 3:




Step 4: