Headlamps, Bi-Xenon

Fig 1: Identifying Bi-Xenon Headlamps Input And Output Signals

Courtesy of VOLVO CARS OF NORTH AMERICA.

1.	Motor, high / low beam	Power supply via relay. Reconnected PWM signal provides information about the position of the reflector to the central electronic module (CEM).
2.	Motor, headlamp range adjustment	Regulated by central electronic module (CEM) via PWM signal.
3.	Position sensor	Inductive sensor that transmits an analogue signal (voltage) to the rear electronic module (REM) (not vehicles equipped with Four-C (Continuously Controlled Chassis Concept)). On vehicles with Four-C, the signal travels via the suspension module (SUM).
4.	Ballast	High voltage regulator for switch and lamp.
5.	Gas discharge lamp	Socket