Engineers design the Passlock™ system in order to prevent the theft of the vehicle if a mechanical key does not start the vehicle. During normal operation, the mechanical key turns the Passlock™ lock cylinder. The Passlock™ lock cylinder relays a resistance code (R-Code) to the instrument cluster. The instrument cluster determines the validity of the R-Code within a preset time window. The window begins when the ignition switch turns. The instrument cluster sends a coded password to the powertrain control module (PCM). If the PCM receives the correct code, the PCM will allow the fuel injectors to operate normally.