High Beams - Halogen Headlamps

WARNING: This page is about a different car, the 2019 Ford F-550 Super Duty, 2019 Ford F-450 Super Duty, 2019 Ford F-350 Super Duty, and 2019 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

The SCCM monitors the LH steering column multifunction switch for a high beam request. When the LH steering column multifunction switch is in the HIGH BEAMS position, the SCCM sends a message over the HS-CAN2 to the GWM, then the GWM sends the message to the BCM over the HS-CAN1.

When the BCM receives a request for high beams, it supplies voltage to the upper headlamp bulbs high beam circuit within each headlamp assembly and sends a message to activate the lower headlamp bulb high beams through the HS-CAN1 to the GWM. The GWM then sends this message through the MS-CAN to the BCMB (Auxiliary Lighting Control Module (ALCM)). When this message is received, the BCMB it supplies voltage to the lower headlamp bulbs high beam circuit within each headlamp assembly.

The BCM also provides Field Effect Transistor (FET) protection of the exterior lamps switched voltage and high beam output circuits. When an excessive current draw is detected, the BCM disables the affected circuit driver. Refer to: Body Control Module (BCM) - System Operation and Component Description .