Normal Operation

WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.

The oil pressure switch is a normally open switch that is hardwired to the smart junction box (SJB) through circuit 1308 (BN/OG). When the oil pressure is within normal ranges, the oil pressure switch closes, grounding the signal to the SJB. The SJB then sends a command signal to the instrument cluster through the communication network, to turn off the oil pressure warning indicator. When engine oil pressure is low, the oil pressure switch opens, removing the ground to the SJB. The SJB sends a low oil pressure command to the instrument cluster through the communication network to illuminate the oil pressure warning indicator. The SJB logs DTC B1306 if circuit 1308 (BN/OG) is open with the engine running or if circuit 1308 (BN/OG) is shorted to ground with the engine off.