Windshield Wipers That Don’t Turn Off or Activate By Themselves (Citroën C3/C4)

This phenomenon is commonly called “BSM Safety Mode”. In Citroën cars, the wipers are controlled via a data network (CAN NetworkIf there is a serious communication failure between the modules, the system is programmed to automatically turn on the headlights and wipers to ensure you are not “blinded” in an emergency.

• Focused Models: Citroën C3 and C4 (all generations).
• Main Causes:
  1. Low or Low Battery: If the voltage drops below the ideal level during starting, the control unit momentarily “malfunctions” and activates the windshield wipers as a safety measure.
  2. Infiltration at BSM: If water gets into the engine fuse box (BSM), it can short circuit and keep the wiper relay stuck.
  3. Defect in COM 2000: The turn signal/wiper switch may have poor contact in the internal circuits, causing it to send a permanently “on” signal.
• Location of Protection (Fuses):
  • If you need to stop the windshield wipers to get to a repair shop on a sunny day, the fuse is located in BSM (under the hood).
  • Correct Fuse: It is usually the F12, with amperage of 30A. Removing it interrupts the power to the front wiper motor.

Diagnostic Tip: If the windshield wipers turn on automatically along with the low beam headlights, there’s a 90% chance the problem is… Battery or Network Communication. If only the wiper turns on and doesn’t respond to the command, the problem is usually in the… BSM internal relay.