Smart Junction Box (SJB)

In addition to being an electrical distribution center for several vehicle systems, the smart junction box (SJB) is a multi-function electronic module, with inputs and outputs for several electrical systems, including the power window system.

During normal operation, the SJB constantly monitors the circuits of electronic systems it controls. If the SJB detects an open, a short to ground or a short to power in the driver-side power window circuits, it will set a diagnostic trouble code (DTC). DTCs can be retrieved with an IDS or equivalent tester. SJB DTCs related to the power window system will not illuminate the malfunction indicator light.