Module, Headlamp Leveling (HLM): Description

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.

Vehicles equipped with the optional headlamp leveling system are also equipped with an Automatic Headlamp Leveling Module (AHLM). The AHLM is located on a bracket behind the passenger side knee air bag, to the right of the HVAC unit.

This module works in conjunction with the front and rear axle (leveling) sensors, the headlamp leveling motors, and electronic message inputs received over the Controller Area Network (CAN) data bus from other electronic modules in the vehicle. The module provides automatic headlamp beam aim adjustment to compensate for changes in vehicle height caused by changes in vehicle loading, acceleration, deceleration, and YAW rate.

Concealed within the module housing is the circuitry of the module itself, which includes a microcontroller. The module is connected to the vehicle electrical system through an integral connector receptacle by a take out and connector of the headlamp and dash wire harness.

The AHLM cannot be adjusted or repaired and, if ineffective or damaged, the module must be replaced. The AHLM is Flash programmable.