Parking Lamps

WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

The SCCM monitors the headlamp switch position by sending voltage signals on multiple circuits to the headlamp switch. There is one circuit for each headlamp switch position. At any given time, one of the signal circuits is switched to ground to indicate the headlamp switch position. The SCCM monitors the headlamp switch position and sends a headlamp switch status message over the HS-CAN to the BCM to indicate the headlamp switch status (position or a fault with the headlamp switch).

If the BCM detects a fault from the headlamp switch or loses communication with the SCCM, the BCM turns the parking lamps and headlamps on and keeps them on until the battery saver feature times out.

If either situation occurs, the BCM cannot be ruled immediately as being at fault. This is normal behavior of the BCM design as a fault has been detected with the inputs from the headlamp switch.

When the BCM receives input requesting the parking lamps on, it energizes an internal relay to provide voltage to the parking lamps. One circuit provides voltage to all of the front parking lamps and a second circuit provides voltage to all of the rear parking lamps.