Headlamp range adjustment (certain markets)

Fig 1: Headlamp Range Adjustment Input And Output Signals

Courtesy of VOLVO CARS OF NORTH AMERICA.

Headlamp range adjustment is controlled by the central electronic module (CEM) (4/56). The central electronic module (CEM) communicates with the light switch module (LSM) (3/111) using serial communication.

If the thumb wheel in the light switch module (LSM) is turned, information about the position of the wheel is transmitted to the central electronic module (CEM). The central electronic module (CEM) transmits a pulse width modulation (PWM) signal to the actuator motors (6/38-39) with the pulse ratio set according to the position of the thumb wheel. The headlamp range can be adjusted in 16 stages.