Smart Junction Box (SJB): Notes

WARNING: This page is about a different car, the 2004 Mercury Monterey and 2004 Ford Freestar. However, it is still accessible from the selected car via links, so may be relevant.

The smart junction box (SJB) is connected to the standard corporate protocol (SCP) communication network. The SJB controls both interior and exterior lighting, body functions, and active anti-theft functions. In the absence of the dual automatic temperature control (DATC) module, the SJB receives input from the function selector switch to operate the manual climate control system. If one of the bus wires becomes shorted to ground or voltage, communications can continue at a degraded level. Check circuits 914 (TO/OG), and 915 (PK/LB ) between the SJB C2280b and the DLC C251. Total resistance values must not be more than 5 ohms. If the resistance is more than 5 ohms, there is an open circuit in the SCP network, damage to the DLC C251, or damage to the SJB C2280b. The SJB is a combination of a multifunction control module and an interior power junction box. SJB functions control multiple systems which include:

illuminated entry and interior lamps
exterior lamps
perimeter alarm
power door locks
auto-locks and smart locks
keyless entry keypad
remote keyless entry (RKE)
warning chimes

The SJB is equipped on all vehicles and is located behind the LH dash closeout panel. For removal information, refer to SMART JUNCTION BOX (SJB) . For additional information on interior lamps and illuminated entry, refer to INTERIOR LIGHTING .