Theory Of Operation
WARNING: This page is about a different car, the 2020 Jeep Renegade. However, it is still accessible from the selected car via links, so may be relevant.
When the Stop Lamp Switch is activated, a hardwired brake signal is sent to the Body Control Module (BCM). When the BCM receives this brake signal, indicating the Brake Pedal is applied, the BCM sends a voltage output through the Stop Lamp Driver circuits and Brake Signal 2 circuit to the Left and Right Tail Lamps, and the Center High Mounted Stop Lamp (CHMSL), which illuminates the Stop Lamps. A separate ground circuit for the Tail Lamps and CHMSL is provided through the wiring harness and is attached to the body sheet metal.