Headlamp Leveling

On vehicles with the HID headlamps, an automatic leveling system is used that includes front and rear axle sensors and an Automatic Headlamp Leveling Module (AHLM) located on the bottom of the right front lamp unit housing. A headlamp leveling motor located on the back of each HID lamp unit is mechanically connected through an integral pushrod to the adjustable headlamp reflector.

The automatic headlamp leveling system automatically adjusts the headlamp beam reflectors to compensate for changes in vehicle suspension height regardless of whether caused by the loading of the vehicle suspension or vehicle pitch changes caused by acceleration and deceleration. The actuator motors are automatically adjusted by the AHLM, which reads the front and the rear axle sensors to determine the suspension height changes. The circuitry of the AHLM provides a voltage signal to the electronic circuitry of both leveling actuator motors and the electronic circuitry of these stepper motors responds to the voltage inputs received from the AHLM to move the headlamp reflectors to the selected position.

The headlamp leveling motors have a path to ground at all times. The automatic headlamp leveling components operate on battery current received only when the exterior lighting and the ignition switch are turned ON.