Headlamp range adjustment position sensors (Bi-Xenon)

Fig 1: Identifying Headlamp Range Adjustment Position Sensor (Bi-Xenon)

Courtesy of VOLVO CARS OF NORTH AMERICA.

Cars with Bi-Xenon lamps have a position sensor so that the headlamps can automatically adjust beam length. The vertical adjustment accounts for load and road conditions to reduce the risk of dazzle.

The position sensor is beside the rear axle and is connected to the left-hand rear control arm by a linkage system. This linkage system affects the sensor, allowing the angle of the car to be gauged.

The position sensor is directly connected to the rear electronic module (REM) via three inputs. Two are used for the power supply and ground connection for the sensor. One input is used for signals about the angle of the car. The signals are received by the rear electronic module (REM) which sends them onwards via the Control area network (CAN) to the central electronic module (CEM) which controls the headlamp range adjustment function.

The position sensor can be calibrated using VIDA. The calibration is saved in the rear electronic module (REM) and must be carried out again if the rear electronic module (REM) or position sensor is replaced.

There are diagnostics for the position sensor.