I changed the car battery & code shows in radio. how do i get the code?

You may have it in your manual or you may have to contact your local dealership.

your car thinks your radio has been stolen since you lost voltage to it.go to or call the dealer with the vin number and proof of ownership,they have that info.check owners manual also should be in it also.they sell a memory saver for this at most parts places to keep from losing any pre-sets,$15.00.