Information related immobilizer,that are classified as 2(two) parts independently, is memorized in EEPROM. PCM check these 2(two) information berfore proceeding immobilizer authentication. With synchronized both information, PCM starts immobilizer authentication procedure. If both information is not synchronized, PCM stops immobilizer authentication, Limphome function will not be activated, and memorizes DTC P1695. If DTC P1695 is retrieved again, after performing new key teaching procedure, PCM should be replaced with new one.