Headlight Auto Leveling System Description (If Equipped)

Headlight Auto Leveling System Description (If Equipped)

System Construction and Operation

Headlight auto leveling system adjusts the optical axis of the headlight automatically to be suitable for the varied vehicle position while the headlights are lit. It consists of front height sensor (1), rear height sensor (2), headlight auto leveling control module (3), headlight leveling actuator (4) and headlight auto leveling warning light (5).





With more passenger(s) or luggage in the vehicle, the vehicle position differs from that in such vehicle state with one person and no load in the vehicle and angle of the headlight optical axis varies accordingly. This system automatically adjusts the varied angle to maintain the optical axis properly.










Front and rear height sensors

Height sensor (1) is installed to the front and rear suspension frames respectively and connected to the lower arm (2) with the link (3). Each height sensor converts vertical movement of the lower arm into the resistance value and outputs the detected change in the vehicle position as a voltage signal to the headlight auto leveling control module.










Headlight auto leveling control module

Headlight auto leveling control module is installed at the foot of the front passenger seat. It uses the headlight ON signal from the lighting switch, vehicle speed signal from BCM and vehicle position signal from height sensors to calculate the angle of the headlight optical axis to be corrected. Then it adjusts the optical axis angle of headlight based on the calculated angle value by driving the headlight leveling actuator so that proper headlight aiming is obtained. Also, when any abnormality is detected in the system, the headlight auto leveling control module makes the headlight auto leveling warning light in the combination meter light up to warn the driver of an abnormality in the system.

Fail-safe function of headlight auto leveling control module

Headlight leveling control module has a fail-safe function which operates as follows.






Headlight leveling actuator

Headlight leveling actuator (1) is located in the headlight housing (2). It moves the reflector (3) in the headlight housing according to the drive signal from the headlight auto leveling control module so as to adjust the optical axis of the headlight to the angle calculated by the headlight auto leveling control module.





Self-Diagnosis Function

The headlight auto leveling control module has self-diagnosis function to monitor the system components and circuits while the headlight auto leveling system is at work. When the headlight auto leveling control module detects an abnormality in the system, the headlight auto leveling warning light in the combination meter turns ON. However, the headlight auto leveling control module does not have a function to indicate location of such abnormality.