GM Service Manual Online
For 1990-2009 cars only

Engineers design the Passlock™ system in order to prevent the theft of the vehicle. Passlock™ disables the engine unless a mechanical key engages the Passlock™ lock cylinder. The system is similar in concept to the Pass-Key® System. Passlock™ eliminates the need for a key mounted resistor pellet. The system contains the following components:

    • The Passlock™ lock cylinder
    • The ignition switch
    • The instrument cluster
    • The powertrain control module (PCM)