Automatic range adjustment (Bi-Xenon)

Fig 1: Automatic Range Adjustment Communication Diagram

Courtesy of VOLVO CARS OF NORTH AMERICA.

Automatic headlamp range adjustment is controlled by the central electronic module (CEM) (4/56). The position sensor (7/120) on the rear suspension transmits signals to the rear electronic module (REM) (4/58) about the angle of the car in terms of the load conditions.

The rear electronic module (REM) transmits this data via the control area network (CAN) to the central electronic module (CEM) which compares the information with the table for the relevant model. The table is stored in the central electronic module (CEM).

The actuator motors (6/38-39) are then operated from the central electronic module (CEM) via a PWM signal, the pulse ratio of which depends on the angle the lamps need to be set to.