Directional Headlight and Leveling Sensor (Citroën C4)

Citroën’s bi-xenon directional headlight system is a work of engineering art, but it has components that can fail due to wear and tear or impacts.

• The Directional Movement: The headlight “rotates” up to $15^{\circ}$ as you turn the steering wheel, thanks to internal micromotors. If an error message appears, the control unit disables the movement for safety reasons, so as not to dazzle oncoming traffic.
• Common Causes of Failure:
  1. Height Sensors: There are two sensors (one on the front axle and one on the rear) that measure the car’s tilt. If one of them breaks (very common after going over deep potholes), the system “gets lost” and locks the headlights in the lowest position.
  2. Lamp at the End of Life: Xenon bulbs ($D1S$) don’t burn out all at once like halogen bulbs; they gradually fade. pink or flashing. When this happens, the reactor (ignition reactor) is overloaded.
  3. Reactor Fuse: Each headlight has its own protection. If only one side doesn’t light up, the problem could be the individual fuse or the ballast itself (which is screwed under the headlight).

Location of Protection (Fuses):

The fuses for the high-intensity lighting system are located in BSM (under the hood):

• Correct Fuse: It’s usually the fuses. F1 and F2 (15A each) From BSM for the medium/Xenon headlights. The steering control module may be connected to the fuse. F10 from BSI.

Maintenance Tip: Never attempt to tamper with the Xenon headlight wiring while the car is running. The system operates at voltages up to… 25,000 Volts Turning the bulb on poses a real risk of serious electric shock. If you need to change the bulb, do so with the battery disconnected.