GM Genuine Parts Anti-Theft Control Modules are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These modules are one part of the vehicles theft deterrent system. When armed, the system is designed to deter vehicle theft by performing one or more of the following: pulsing the horns and exterior lamps when unauthorized vehicle entry is detected, or prevent starting of the engine without an authenticated ignition key. This module may manage the system functions independently or in conjunction with other modules and components within the vehicle. GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE).