If a new one it should come with a code to insert.
If second hand and no code you'll have to get it recoded look online for a local recoder outlets and give serial number make and model of the radio. Or drive to them let them pull it out again and check the serial number.
Bob U.K.
December 2012
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cd players.