Have Ford Questions? Ask a Mechanic for Answers ASAP
Hello, when the THEFT lamp flashes its because it cannot read the security chip in the ignition key. If you have a second ignition key se if it will prove out the theft lamp and start. if it still wont it can be a bad key, key transponder or issue with the PATS anti theft module. A diagnostic check for codes of the security system would tell you more. A local locksmith should have a diagnostic scan tool capable of testing the system and reprogramming keys if needed. You must have 2 keys to reprogram the PATS system
First lets get some more info, what kind of vehicle, year make model, engine, was it running fine then just acted up or something was recently done and now you have this problem?