Renault Radio Unlocker will provide you with the security code required to activate your Renault car Radio/CD player following a loss of power. To find your code just follow these steps: - Remove the Radio/CD player from the dashboard using the recommended release keys - Find the serial number - this is normally on a label located on the casing (further information in the app) - Enter the serial number into the app to generate the unlocking code for your Radio/CD player The app can supply codes for all serial numbers which begin with one letter followed by three numbers. It will also work with some other radios made by Phillips.