Exterior Lighting - System Operation and Component Description: Stoplamps
WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
System Diagram
Stoplamps
The brake pedal switch is part of the EBB. When the brake pedal is applied, the PCM sends a message over the HS-CAN1 to the BCM. When the BCM receives the message, the BCM then supplies voltage to the stoplamps.
The BCM does not activate the stoplamps when the ignition is in OFF or ACC.
The BCM uses 3 separate output circuits. The LH stop lamp output circuit, RH stop lamp output circuit and high-mounted stoplamp output circuit.
The BCM also provides Field Effect Transistor (FET) protection of the stoplamp output circuits. When an excessive current draw is detected, the BCM disables the affected stoplamp circuit driver.