A method and system for relearning a previously programmed, authenticated key. The system includes an electronic control module (ECM) and a key. The method begins when the ECM fails to match an identification code (ID) of the key with all active or disabled IDs that are stored within the ECM. Thereafter, the ECM sends a signal to the key by encryption with a default secret code. If the key does not respond to this signal, then the ECM sends a signal to the key by encryption with one of a series of unique secret codes. The key receives this signal and then transmits an encrypted valid response signal to the ECM. The ECM extracts a key password from the encrypted valid response signal and compares this key password to a module password. Thereafter, the ECM determines that the passwords are identical and the ECM stores the key ID.