The engine control module, mostly referred to as the ECM / PCM, is a computerized unit that processes incoming sensor data and then uses the data to control certain function's output. Since the 1980’s the engine computer has been relied on for fuel injection data, emission control, climate control and directly communicates with the ABS module . Now in modern vehicles the ECU will compile data from both intake and exhaust, your cooling system, your camshaft positions which is known to trigger a check engine light if your engine computer is faulty or on it’s way out.
