iI have a blaupunkt radio in my s reg.if your radio reads error 3 for example , it means you or someone has tried to enter the code 3 times , then it reads 4 and so on.
to remove the word error , switch on your radio and just leave it for a couple of hours ,when you return it will display - - - -. now you can enter your code using the digits on your radio .
for number (example) 6382 press digit 1 6times
next press digit 2 3times
now press digit 3 8 times
and digit 4 twice
your radio will display 6382 and should now work.
dont forget all radios have a unique code and if you dont have it you can aquire it from the internet at a price approx 8 pounds, you will need the serial number and product code from the rear of your radio to get this.
mel.w, March 2010