You should have a small card in with your hanbook etc. This card will have a four digit code which you need to input into your radio. You can also find in your handbook how this code is entered. If the code is missing, you will need to find one of many firms offering a code service online. Usually you need the code details from the label on the back of the radio and the code can be obtained for you. There is a charge for this service.

Hope this helps

Robin the Technician - I fix, therefore I am

Where abouts are you based?