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	Controlled by the central electronic module (CEM) using a PWM signal.
3.	Position sensor	Inductive sensor which sends an analog signal (voltage) to the rear electronic module (REM) (Does not apply to vehicles with Four-C (Continuously Controlled Chassis Concept)). In 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