Normal Operation

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 SJB communicates with the diagnostic tool through the standard corporate protocol (SCP) communications network circuits 914 (TN/OG) and 915 (PK/LB). If one of the bus wires becomes shorted to ground or voltage, communications can continue at a degraded level. Check circuits 914 (TN/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 fused power (overload protected) is supplied by the bussed electrical center (BEC). Circuits 1052 (TN/BK), 1523 (DG), and 1524 (DB) supply power to the SJB. The SJB is grounded through circuit 1205 (BK).