Principles of Operation: Notes
WARNING: This page is about a different car, the 2009 Mercury Sable, 2009 Ford Taurus X, and 2009 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
The smart junction box (SJB) is also known as the generic electronic module (GEM).
The smart junction box (SJB) monitors the input from the stoplamp switch. When the brake pedal is applied, voltage is routed to the SJB and the high mounted stoplamp (and the rear lamps for Sable). For Taurus and Taurus X, the SJB then supplies voltage to the rear lamps.
NOTE:
The SJB cannot determine if the rear lamp is inoperative for Taurus X. A visual inspection is required to determine if the rear lamp is inoperative.
If the rear stoplamps are combined with the turn lamps, the turn and hazard lamp functions override the rear stoplamp function.