Automatic Headlight Leveling

Fig 1: Identifying Headlamp Control Module (HCM) & Components

Courtesy of VOLVO CARS CORPORATION

Position sensors (7/120-121) on the rear and front wheel suspensions send information to Headlamp Control Module (HCM) (4/114) about the vehicle's angle depending on load conditions, acceleration, and braking.

Headlamp Control Module (HCM) uses information from the position sensors to calculate current angle for the headlights.

For vehicles with active headlights and GDL-lights, Headlamp Control Module (HCM) sends information bout current angle to Left headlamp control unit (LHCU) and Right headlamp control unit (RHCU) via serial communication.

The actuators are controlled from Left headlamp control unit (LHCU) and Right headlamp control unit (RHCU).