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

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

U1-U2:

U2-U3:

U4-U6:

U6-U7:

U8-U10:

U10-U14:

U14-U17:

U18-U22:

U22-U26:

U26-U30:

U30-U33:

U33-U35:

U35-U39:

U39-U42:

U43-U47:

U47-U51:

U51-U55:

U55-U57:

U58-U61:

U62-U66:

U67-U70:

U71:

Normal Operation
The MS-CAN network uses an unshielded twisted pair cable, circuits VDB06 (GY/OG) and VDB07 (VT/OG) provide the network connection to all modules on the network. The smart junction box (SJB), the instrument cluster, the electronic manual temperature control module (if equipped), the electronic automatic temperature control (EATC) module (if equipped), the audio unit, the THX(R) amplifier (if equipped), the satellite radio receiver (if equipped), the auxiliary audio module (if equipped), the digital versatile disc (DVD) (if equipped), the power running board module (if equipped), the parking aid module (if equipped), the power liftgate module, the driver seat module, and the climate controlled seat module (if equipped) all communicate with the scan tool using the MS-CAN network.

Possible Causes
- Circuit VDB06 (GY/OG) open, short to ground or voltage (MS-CAN +)
- Circuit VDB07 (VT/OG) open, short to ground or voltage (MS-CAN -)
- Circuit VDB06 (GY/OG) (MS-CAN +) and circuit VDB07 (VT/OG) (MS-CAN -) shorted together
- SJB
- Instrument cluster
- Audio unit
- THX(R) amplifier (if equipped)
- EATC module (if equipped)
- Electronic manual temperature control module (if equipped)
- Auxiliary audio module (if equipped)
- DVD player (if equipped)
- Driver seat module (DSM) (if equipped)
- Climate controlled seat module (if equipped)
- Satellite radio receiver (if equipped)
- Power running board module (if equipped)
- Parking aid module (if equipped)
- Power liftgate module (if equipped)