Bulb Burnout and Turn Signal Switch Failure (COM 2000) (Citroën C3)

The C3’s lighting system is electronically managed. When malfunctions occur, the problem can range from simple excessive vibration to a chronic defect in the steering wheel control module.

• Focused Model: Citroën C3 (Generation 1 and 2).
• The Problem with Light Bulbs: Frequent light bulb burnout (especially the H7 (low beam headlights) usually occur for two reasons:
  1. Lighthouse Vibration: If the headlight bracket is loose, the constant vibration will break the bulb filament.
  2. Voltage Spikes: Faults in the alternator voltage regulator can send overload to the system.
• The Turn Signal Switch Problem (COM 2000): If the turn signal doesn’t “lock” on, or if the headlight turns on by itself when using the turn signal, the problem is in the control unit. COM 2000 (the set of levers behind the steering wheel). This component suffers wear on the internal contact tracks.

Location of Protection (Fuses): If the headlights stop working completely (and it’s not the bulb), the fuses are located in BSM (under the hood):

• Right Low Beam: Fuse F10 (15A).
• Left Low Beam Headlight: Fuse F09 (15A).
• High Beam: Fuses F11 and F12 (15A).

Technical Tip: Never replace a burnt-out bulb with a higher wattage one (e.g., putting a 100W bulb where a 55W bulb is required). This melts the plastic connector and overloads the BSM, potentially causing significant damage to the electronic control unit.