Radio Brands: Blaupunkt, Clarion, Philips, VDO, Bosch.
⚠️ IMPORTANT WARNING: THE "BEEPING" RADIO
If your Citroën radio is playing music but emitting a loud, continuous "BEEP" every few seconds, a 4-digit PIN code will NOT fix this. This happens on modern multiplexed models (like the C2, C3, C4, C5 with RD4 / RT3 / RT4 units). The radio needs to be electronically paired (VIN-coded) to your car's engine computer using a Citroën diagnostic tool (Lexia/Diagbox) at a garage. Do not buy this code if your radio is beeping.