GM Genuine Parts Automatic Transmission Control Solenoids are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These solenoids are electro-hydraulic valves that help control the flow of fluid within the control valve body. They also help control clutch application pressure. 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).