Principles of Operation
WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The Steering Column Control Module (SCCM) monitors the fog lamp switch and sends a message over the High Speed Controller Area Network (HS-CAN) to the Body Control Module (BCM) to indicate the fog lamp switch position.
The fog lamps can be turned on when the following conditions are met:
- The ignition is in the RUN or START state.
- The low beam headlamps or the parking lamps are on.
- The high beams are off.
When the BCM receives an input from the headlamp switch indicating a request for the fog lamps, the BCM provides ground to the fog lamp relay (integrated into the BCM). When the fog lamp relay is energized, voltage is routed to the fog lamps.