Anti-Theft

• Three types of anti-theft systems are used by General Motors in their vehicles, which are Pass-Key, Passlock and Passkey 3. The Passlock system is designed to prevent the operation of the GM vehicle when the automobile is started without the correct key.
  
  

Code

• When the key drum is turned, it passes a magnet that sends a code to the instrument panel, which passes on the code to the Powertrain Control Module. The correct code must pass along these systems in a short space of time to allow the vehicle to operate.
  
  

Tamper

• On the first attempt to start, a Passlock system will disable the vehicle in short tamper mode, which disables the vehicle for 4 seconds. After three failed attempts the long tamper mode disables the vehicle for ten minutes.