Catch all tag which can refer to the "brain" of the car which can control the engine and/or transmission of the vehicle. This would include such terms as PCM (powertrain control module), ECM (engine control module), PCU (powertrain control unit), ECU (engine control unit), and many, many others.
Need a computer pin out diagram. Cylinder 3 miss firing. Need to check wiring. Plug and coil pack are good, but no spark.