I drive a 2009 Kia Rio Hatchback. A few days ago the car battery was replaced and I can't get the K100R radio to work.
Last time my car lost power and was jump-started, I was able to input a 4-digit code to unlock the radio (so I know the code is correct). This time, it won't accept the code and just displays "CD1".
I don't know what this means. What can I do to make it work again?