Theory Of Operation

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

Incandescent High Beam Lamps: When High Beam Lamp illumination is requested, a communication network message from the Steering Column Control Module (SCCM), or the Forward Facing Camera (FFC) Module/Driver Assistance System Module (DASM), if equipped, is sent to the Body Control Module (BCM). When this message is received, the BCM provides a Pulse Width Modulated (PWM) voltage, through the Left and Right High Beam Driver circuits, to the Left and Right Front Lamp Assemblies. A separate ground circuit is provided to the Left and Right Front Lamp Assemblies through the wiring harness.

LED High Beam Lamps: When High Beam Lamp illumination is requested, a communication network message from the Steering Column Control Module (SCCM), or the Forward Facing Camera (FFC) Module/Driver Assistance System Module (DASM), if equipped, is sent to the Body Control Module (BCM). When this message is received, the BCM provides a voltage signal, through the Left and Right High Beam Driver circuits, to the Left and Right Front Lamp Assemblies. When this voltage signal is received, the Left and Right Front Lamp Assemblies provide the Pulse Width Modulated (PWM) voltage to activate the Left and Right High Beams. A separate ground circuit is provided to the Left and Right Front Lamp Assemblies through the wiring harness.