GM Genuine Parts Engine Control Modules are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These modules regulate various parts of your vehicle's engine by receiving input from sensors and additional modules and then referencing that information back to other sensors, modules, and areas of 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).