stereochemistry (stÄr'Ä-Å-kÄm'Ä­-strÄ) The branch of chemistry that deals with the spatial arrangements of atoms in molecules and with the chemical and physical effects of these arrangements.
ECU. Short for Electronic Control Unit, the ECU is a name given to a device that controls one or more electrical systems in a vehicle. It operates much like the BIOS does in a computer.
LEARN MORE. The engine control module (ECM), also commonly referred to as the engine control unit (ECU) or powertrain control module (PCM), is one of the most important components found on virtually all modern vehicles. It essentially functions as the main computer for many of the vehicleâs engine performance and drivability functions.