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

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

E1-E3:

E3-E4:

Normal Operation
The SJB communicates with the scan tool through the medium speed controller area network (MS-CAN). Circuits 2180 (WH/BK) (MS-CAN +) and 2181 (BK/YE) (MS-CAN -) provide the network connection to the SJB. The SJB shares the MS-CAN network with the electronic automatic temperature control (EATC) module, the audio unit, the driver seat module (DSM), the digital versatile disc (DVD) player, the satellite radio receiver, and the instrument cluster. Voltage for the SJB is provided by redundant circuits. Circuits 483 (RD) and 1566 (RD/YE) provide voltage, and circuit 1203 (BK/LB) provides ground.

Possible Causes
- Fuse
- Circuit 1203 (BK/LB) open
- Circuit 1205 (BK) open
- Circuit 1231 (RD/WH) open
- Circuit 2180 (WH/BK) open (MS-CAN +)
- Circuit 2181 (BK/YE) open (MS-CAN -)
- SJB