i just replaced my battery, but all of a sudden my cd player has started asking for a code and my anti-theft light is blinking...does any one know the code that will unlock my cd player

 

The code is unique for each radio. It's an anti-theft feature.

Sometimes the code is hidden in the car. (--->Side of glove box, inside fuse box, etc.) Search the forum for places to look. And some dealers can give you the code. (Some dealers will also charge for this.)

I got the security codes for both my navigation system and my radio over the phone from the dealership that originally sold the car. They just needed the car's VIN number.