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 low coolant level switch is hardwired to the smart junction box (SJB) through circuit 794 (LB) and grounded through circuit 1205 (BK). The SJB monitors the coolant level and sends the coolant level data to the instrument cluster over the communication network.