If it displays SAFE all the time then it usually means that too many wrong codes have been entered and it is now locked.
If it`s not a stolen radio then a "reset " solution might be possible ..details from website below.....otherwise it will be a trip to your Main Dealer or Radio Decode Specialist for the radio to be unlocked using specialist kit.
www.tinyurl.com/4ydhop
RegWorts
July 2008