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:

H1-H3:

H3-H4:

H5:

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 audio unit, the satellite radio receiver (if equipped), the driver seat module (DSM) (if equipped), the parking aid module (if equipped), the power running board module (if equipped), and the digital versatile disc (DVD) player (if equipped). Voltage for the SJB is provided by circuit SBB03 (BU/RD). Circuit GD108 (BK/VT) provides ground.

Possible Causes
- Fuse
- Circuit SBB03 (BU/RD) open
- Circuit GD108 (BK/VT) open
- Circuit VDB06 (GY/OG) open (MS-CAN +)
- Circuit VDB07 (VT/OG) open (MS-CAN -)
- SJB