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

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

Normal Operation
The smart junction box (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, audio unit, electronic automatic temperature control (EATC) or electronic manual temperature control (EMTC) module, satellite radio receiver, front control interface module (FCIM) and front display interface module (FDIM). Voltage for the SJB is provided directly from the internal SJB busbar through SJB fuse 5 (10A). Ground is provided by circuit GD182 (BK/GY).

This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- SJB

J1-J2:

J3-J4: