DTC 12: Encrypted Codes are not identical or not Registered: Diagnosis
WARNING: This page is about a different car, the 2005 Dodge Stratus and 2005 Chrysler Sebring. However, it is still accessible from the selected car via links, so may be relevant.
Was the encrypted code registered?
YES : Replace the immobilizer-ECU and then re-register the encrypted code (Refer to SPECIAL TOOLS ).
NO: Register the encrypted code (Refer to SPECIAL TOOLS ).