GM Genuine Parts HVAC Blower Motor Control Modules are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These modules are microprocessor computers that modulate HVAC blower speed. The control module receives input from the HVAC control module. 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).