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Test H: The Smart Junction Box (SJB) Does Not Respond To The Scan Tool

PINPOINT TEST H: THE SMART JUNCTION BOX (SJB) DOES NOT RESPOND TO THE SCAN TOOL


H1-H2:






H2-H3:






H4:






Normal Operation
The SJB communicates with the scan tool through the medium speed controller area network (MS-CAN). Circuits VDB06 (GY/OG) (MS-CAN +) and VDB07 (VT/OG) (MS-CAN -) provide the network connection to the SJB. The SJB shares the MS-CAN network with the instrument cluster, the electronic automatic temperature control (EATC) module (if equipped), the dual automatic temperature control (DATC) module (if equipped), the audio unit, the THX(R) amplifier (if equipped), the satellite radio receiver (if equipped), the driver seat module (DSM) (if equipped), the driver door module (DDM) (if equipped) and the climate controlled seat module (if equipped). Voltage for the SJB is provided by circuit SBB19 (BU/RD). Circuit GD116 (BK/VT) provides ground.

Possible Causes
- Fuse
- Circuit GD116 (BK/VT) open
- Circuit SBB19 (BU/RD) open
- Circuit VDB06 (GY/OG) open (MS-CAN +)
- Circuit VDB07 (VT/OG) open (MS-CAN -)
- SJB