Normal Operation
WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The smart junction box (SJB) monitors the hood ajar switch on circuit 1304 (VT/OG) to prevent the alarm from being armed while the hood is open. If the SJB does not see an ground signal on circuit 1304 (VT/OG) the SJB will not arm the alarm. The hood ajar switch is grounded by circuit 570 (BK/WH).