Pinpoint Test 8: The Smart Junction Box (Sjb) Does Not Respond to the Scan Tool

PINPOINT TEST 8: 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 (GY/O) (MS-CAN +) and (VT/O) (MS-CAN -) provide the network connection to the SJB. The SJB shares the MS-CAN network with the instrument cluster, electronic manual temperature control (EMTC) module, audio unit, 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 (10 A). Ground is provided by circuit (B/GY).

Possible Causes
- Fuse
- Wiring, terminals or connectors
- SJB

Diagnostic Procedure

CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

Step 1-Step 4: