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

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

D1:

D2-D4:

D4-D5:

Normal Operation
The SJB communicates with the scan tool through the standard corporate protocol (SCP) communication network. Circuits 914 (TN/OG) (SCP +) and 915 (PK/LB) (SCP-) provide the network connection to the SJB. The SJB shares the shares the SCP network with the electronic automatic temperature control (EATC) module or electronic manual temperature control (EMTC) module, the speed control actuator and the instrument cluster. Voltage for the PCM is provided by circuits 1523 (DG), 1524 (DB) and 1052 (TN/BK). Circuits 1205 (BK) provide ground.

Possible Causes
- Fuse
- Circuit 914 (TN/OG) open (SCP +)
- Circuit 915 (PK/LB) open (SCP -)
- Circuit 1052 (TN/BK) open
- Circuit 1205 (BK) open
- Circuit 1523 (DG) open
- Circuit 1524 (DB) open
- SJB