XC90 FWD L6-3.2L VIN 98 B6324S (2007)
Headlamp Control Module: Description and Operation
Active headlights are an intelligent headlight system that optimizes illumination of the road surface at night by turning out the light beam. The motorized
headlights are controlled by the headlight control module (HCM), which retrieves signals from the CAN network.
In order to activate the active headlight function, the headlight control module (HCM) (4/118) needs information on the following: vehicle speed, current
gear, light conditions.
The headlight control module (HCM) receives information from the following control modules:
Brake control module (BCM) (4/16) for information on vehicle speed
Transmission control module (TCM) (4/28) for information on current gear (automatic transmission)
Central electronic module (CEM) (4/56) for information from the reversing light switch (3/10) (manual transmission)
Central electronic module (CEM) for information from the twilight sensor (7/12)
The headlight control module (HCM) is activated automatically when the ignition switch is turned to position II. In order to turn out the light beam, the
following conditions must be fulfilled:
The vehicle must be in motion, that is to say travelling at a speed greater than 3.6 km/h (2.2 mph).