Abstract: A vehicle anti-theft method for use in a vehicle having an internal combustion engine, an ignition, a starter, fuel injectors, a memory, engine controller, and a real clock time function in the engine controller, said engine controller being configured to operate the engine in a plurality of different modes including a theft protection mode, comprises; a) comparing a lock window definition time with an engine controller real clock time; b) operating the engine in a theft protection mode when the real clock time matches the lock window definition time; c) determining whether the engine is running, and; d) controlling the operation of the engine.