How does a passlock sensor work?

A Passlock sensor is part of a vehicle's anti-theft system that detects the ignition key's presence and verifies its authenticity. It typically consists of a magnetic switch or a resistor that generates a unique code when the key is turned in the ignition. The vehicle's computer reads this code, and if it matches the stored value, it allows the engine to start. If the code is incorrect or absent, the system disables the engine, preventing theft.