Module, Headlamp Leveling: Description: Description
Vehicles equipped with the optional High Intensity Discharge (HID) headlamps are also equipped with an Automatic Headlamp Leveling Module (AHLM) (1) (also known as the Headlamp Leveling Module/HLM). The AHLM is located on the underside of the right front lamp unit housing, but serves both the right and left front lamp units. This module works in conjunction with the front and rear axle sensors and the headlamp leveling motors to provide automatic headlamp beam adjustment to compensate for changes in vehicle height caused by changes in vehicle loading, acceleration or deceleration.
The molded black plastic AHLM housing has integral mounting flanges (4) that are secured by a stamped aluminum cover plate and four screws to a receptacle in the bottom of the right front lamp unit housing. Concealed within the housing is the circuitry of the module, which includes a microprocessor. The module is connected through an integral connector receptacle (2) to the vehicle electrical system by a take out and connector of the right front lamp unit wire harness.
The AHLM cannot be adjusted or repaired and, if ineffective or damaged, it must be replaced.