[OrangeTungsten] determined that the door projectors that project the Citroën logo onto the ground frequently failed to work because of the Hall effect sensor that detects the magnet. After the magnet fell out of position, the sensor was removed and replaced with a simple button that makes physical contact with the door frame.
During the examination, an 8-pin microcontroller was found in the projector that appeared to turn the LED on and off solely by controlling the sensor. The projectors were brought back into operation through the hardware modification.
Why it matters
This example shows that the failure may stem not from the projector’s entire electronic structure, but from the triggering mechanism that detects the opening and closing of the door. This suggests that, for Citroën owners using similar accessories, the repair could focus on a single detection component rather than replacing the entire part. Switching to a mechanical button eliminates the need to keep the magnetic component in position, while introducing a new mode of operation that depends on physical contact with the door frame. The fact that the visible function of the microcontroller in the projector appears to be limited to controlling the LED also indicates that the failure is concentrated in the triggering stage rather than in a more complex electronic control system. The unresolved issue is how durable this simple solution will be in long-term use.