Pinpoint Test 13: No Medium Speed Controller Area Network (MS-CAN) Communication, All Modules Are Not Responding

PINPOINT TEST 13: NO MEDIUM SPEED CONTROLLER AREA NETWORK (MS-CAN) COMMUNICATION, ALL MODULES ARE NOT RESPONDING

Normal Operation

The medium speed controller area network (MS-CAN) uses an unshielded twisted pair cable, circuits (GY/O) and (V/O). The smart junction box (SJB), audio control module (ACM), satellite digital audio receiver system (SDARS) module, front display interface module (FDIM), front controls interface module (FCIM), and the HVAC module communicate with the scan tool using the MS-CAN. The instrument cluster (IC), while on the MS-CAN, communicates with the scan tool only on the HS-CAN.

Possible Causes
- Wiring, terminals or connectors
- IC
- SJB
- ACM
- FCIM (if equipped)
- SDARS module (if equipped)
- FDIM
- HVAC module

Diagnostic Procedure

CAUTION:Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE:Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the Pinpoint Test.
NOTE:Failure to disconnect the battery when instructed will result in false resistance readings. See Battery Disconnect.

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