You have a problem with your car radio which is locked with code or car radio needs password to unlock, when car battery is Disconnected/Replace. This App takes ERC number and decodes it into ERC unlock code/password when entered in Audio Unit restores various functions of unit i.e. Radio, CD, DVD Player, BT, Navigation and other functions of unit where applicable. Save your original radio. Don’t buy a new one. Restore it to regain full use. This applies to approx. 99% Japanese Car Radio/Audio with Navigation and Touchscreen but not valid for Single-DIN stereos. Just Input the 16 Digit ERC code (Not Serial or any other number written in car radio physically probably at top or back side) of Car Radio/Audio player (You can get ERC code by following the very easy steps mention in video) and Get the 8 Digit unlock code instantly using that app. How to find ERC Number Press and hold the main button on your navigation player and turn on off your parking lights 3 to 4 times until a new screen appears. Press only active button, on screen and you will get the screen where is your 16-digit serial number appear. If you are unable to get ERC code of your player, then write to [email protected] The Money Back and Low Price Guarantee If provided ERC unlock code does not work with your Car Radio, then we'll be happily giving you your money back on your request without any question.