I have a 2002 Jag xj8 and I got a SIRIUS radio which worked. I then replaced the battery and the radio asked for a code. I called the dealer and it gave me a code which correlated with my VIN number. This number does not work. Could it be that the adding of the SIRIUS radio caused a disturbance in the security? Or do I need to remove my radio to get a number on the back of the radio? How do I get the correct passcode?

Greg LeBouton, May 2008

If the radio is the original one that came with the car from new, then the problem is either the dealer gave you the wrong code or you are entering it incorrectly.
Check the entry method here

http://www.davidsonelectronics.co.uk/code_entry.htm

RegWorts, May 2008