Headlamp Leveling Module - Description

DESCRIPTION





An Automatic Headlamp Leveling Module (AHLM) (also known as the High Intensity Discharge Transducer/HIDT) (1) is used only on vehicles manufactured for certain export markets equipped with the optional High Intensity Discharge (HID) headlamps. The AHLM is located on the top of the left rear wheel housing within the passenger compartment and 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 cased by changes in vehicle loading, acceleration or deceleration.

The molded black plastic AHLM housing has integral mounting flanges that are secured to two studs (2) on a stamped metal mounting strap (4) by two nuts. Two additional nuts secure the mounting strap to two studs located on the top of the left inner rear wheel housing. Concealed within the housing is the circuitry of the module, which includes a microprocessor. The module is connected through an integral connector receptacle (3) to the vehicle electrical system by a take out and connector of the body wire harness. The AHLM is concealed behind the left quarter inner trim.

The AHLM cannot be adjusted or repaired and, if ineffective or damaged, it must be replaced.