Trailer Stop-Turn Lamps

WARNING: This page is about a different car, the 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

The SCCM monitors the LH steering column multifunction switch position. When the LH steering column multifunction switch is in the left or right turn 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 indicating a request for the LH or RH turn signal.

When the BCM receives a request for a turn signal, the BCM provides a switched ground path to the LH or RH stop/turn trailer tow relay (integral to the BJB). When the BCM provides ground the LH or RH stop/turn trailer tow relay, the relay is energized and the relay provides turn lamp voltage to the trailer tow connector.

When the BCM receives input from the stoplamp switch indicating that the brake pedal is being pressed, the BCM provides a ground path to the LH and RH stop/turn trailer tow relay (integral to the BJB). When the BCM provides ground the LH and RH stop/turn trailer tow relay, the relay is energized and the relay provides stop lamp voltage to the trailer tow connector.