Turn Signals - Front

WARNING: This page is about a different car, the 2018 Lincoln Navigator. 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 LH TURN or RH 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 ignition is ON, the BCM supplies voltage to the adaptive front lighting module through the turn lamp voltage output circuit to power the turn lamp Light Emitting Diodes (LEDs) when commanded on.

When the BCM receives a request for a turn signal, it sends a message over the LIN circuit to the adaptive front lighting module attached to each headlamp assembly. The turn lamps are Light Emitting Diodes (LEDs) and have an outage circuit that tells the BCM when the Light Emitting Diodes (LEDs) are inoperative. During normal operation, when the adaptive front lighting module applies voltage to the turn Light Emitting Diodes (LEDs), the feedback circuit sends the same voltage back to the BCM through the outage circuit. If the Light Emitting Diodes (LEDs) are inoperative the BCM does not receive this voltage feedback through the outage circuit.

The BCM also provides Field Effect Transistor (FET) protection of the turn lamp output circuits. When an excessive current draw is detected, the BCM disables the affected turn lamp circuit driver. Refer to: Module Controlled Functions - System Operation and Component Description .