Xenon headlights – how do they work and what usually breaks down in them?

Currently produced cars with xenon or bi-xenon headlights are equipped with both automatic range adjustment (so-called leveling) and cleaning systems. The first of them reacts to changes in inclination resulting from the driving condition, while the second enables effective cleaning of the headlight lenses with the help of special water sprayers, which replaced the previously used mechanical wipers.

Audi A4 B8.5 - Bi xenon
Audi A4 B8.5 – Bi xenon


In vehicles equipped with xenon (or bi-xenon) headlights, the so-called dynamic beam range adjustment system. How it’s working? This system reacts to changes in inclination resulting from a given section of the ride, e.g. as a result of acceleration or braking, based on data from the sensors. In order to react quickly to changes in vehicle inclination, electric stepper motors are used to control the headlights: the impulse power supply used in them causes their rotors to rotate only by a strictly defined angle (unlike traditional electric motors in which the rotor rotates continuous motion). In addition, the dynamic headlight range control system includes: electric headlight range adjusters, an automatic and dynamic headlight range adjustment system controller, and an inductive vehicle level sensor.


High-intensity xenon headlights with gas-discharge lamps can cause glare as a result of contamination of their lampshades. Therefore, the sprinklers at the xenon headlights are mounted on the basis of the regulations set out in the ECE approval regulations (United Nations Economic Commission for Europe), specifically in accordance with ECE Regulation No. 48. It is worth knowing that in the European Union the obligation to mount a cleaning system for xenon headlights was introduced in 1996.


The xenon headlight cleaning system with water spraying fails, as do other systems used in cars. The most common reason is the impeller pump not working or the water nozzle clogged. Inability to start the pump may be due to a lack of supply voltage or a blown fuse. Sometimes a blown-up washing system is to blame for this. To restore its proper functioning, the system must be completely vented by repeated attempts to start the pump. If the nozzle is clogged, it is necessary to remove foreign matter and rinse the entire system thoroughly. In the winter season, on the other hand, the xenon headlight cleaning system is exposed to ice. It usually helps to increase the amount of antifreeze. We should remember, that in the case of longer parking “under the cloud” (eg after a very cold night), this may not be enough and you will need to leave the car in a warmer place for some time.

UpgradeMyAudi.net TEAM

Audi maniac, owner of upgrademyaudi.net and big fan of Audi cars. Maps, firmware, car audio installer
Notify of

Inline Feedbacks
View all comments