Electronic Control Module

From GM Wiki

ECM is an Acronym for Electronic Control Module. This is the computer that controls the engine and it's Electronic Fuel injection, as well as the car's emissions. ECM is generally an OBD I term, and OBD II computers are PCM or BCM because they are more sophisticated and can control the entire powertrain (PCM) or even controls everything on the body (BCM). The ECM that is found in v6 J-bodies are 1227730.