Engine Control Module (ECM)

PURPOSE/OPERATION
The electronic control module controls the fuel injection system, ignition timing, and the idle speed control system. The engine control module also interrupts the operation of the air conditioning and EGR systems, and controls power to the fuel pump (through the control relay). Based on information from the input sensors (engine coolant temperature, barometric pressure, air flow, etc.), the engine control module determines optimum settings for the output actuators (injection, idle speed, ignition timing, etc.).