Radio beeping

[HartlepoolMike]

Hi, I just bought a C2, 57 plate, and it had a nasty aftermarket stereo so I bought an OEM stereo off ebay. It is made by Continental, model RD4N1M-03. Before I bought it I made sure I got a security code for it. When I installed it, however, it didn't ask for the code, it just beeps. How do I stop this?

[GiveMeABreak]

There's no such thing as security codes for RD4 units - they are VIN-coded to the vehicle and this requires a Lexia or other professional level diagnostic tool or you will have beeps forever.