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 Body Control Module (BCM) receives a hardwired input signal from the Headlamp Switch, requesting Headlamp Low Beam illumination, the BCM provides a Pulse Width Modulated (PWM) voltage output through the Left and Right Low Beam Driver circuit to the Left and Right Front Lamp Assemblies. A separate ground circuit for the Left and Right Front Lamp Assemblies is provided through the wiring harness to the body sheet metal.