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

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

O1-O2:

O3-O4:

O5-O7:

O7-O9:

O9-O11:

O11-O13:

O13-O15:

O15-O17:

O17-O19:

O19-O21:

O21-O24:

O25-O28:

Normal Operation
The MS-CAN uses an unshielded twisted pair cable, circuits 2180 (WH/BK) and 2181 (BK/YE). The smart junction box (SJB), the electronic automatic temperature control (EATC) module, the audio unit, the driver seat module (DSM), the digital versatile disc (DVD) player, the satellite radio receiver, and the instrument cluster all communicate with the scan tool using the MS-CAN.

DTC U1900 (audio unit) - sets when the MS-CAN bus performance is compromised.

DTC U1900 (DSM) - sets when the MS-CAN bus performance is compromised.

DTC U1900 (SJB) - sets when the MS-CAN bus performance is compromised.

DTC U1901 (instrument cluster) - sets when the MS-CAN bus performance is compromised.

Possible Causes
- Circuit 2180 (WH/BK) open, short to ground or voltage (MS-CAN +)
- Circuit 2181 (BK/YE) open, short to ground or voltage (MS-CAN -)
- Circuit 2180 (WH/BK) (MS-CAN +) and circuit 2181 (BK/YE) (MS-CAN -) shorted together
- SJB
- EATC module
- Audio unit
- DSM
- DVD player
- Satellite radio receiver
- Instrument cluster