Powertrain Management: Description and Operation

System Components Typical:

ECM SYSTEM
The computerized engine control system is built around an Engine Control Module (ECM). The ECM receives inputs and responds with appropriate outputs to manage fuel delivery, ignition timing, and emission control devices, charging system, speed control and idle speed. The ECM is a pre-programmed, dual microprocessor digital computer.

The ECM controls fuel delivery. Fuel is injected into the intake manifold before the intake valve in precise amounts through electrically operated injectors. The injectors are fired in a specific sequence by the ECM. As operating conditions change, the ECM adjusts injector pulse width (the length of time the injector is energized) and ignition timing for optimum performance and fuel economy.

The ECM also adjusts the ignition timing by controlling the ignition coil dwell.

ECM INPUTS
^ A/C Compressor Clutch Relay
^ Barometric Pressure Sensor
^ Camshaft Position Sensor
^ Crankshaft Position Sensor
^ Engine Coolant Temp Sensor
^ Exhaust Gas Recirculation
^ Ignition Coil, [1][2]Ignition Power Transistor Unit
^ Igniton Timing Adjustment Signal
^ Induction Control Valve Position Sensor
^ Fuel Injectors
^ Intake Air Temperature Sensor
^ Knock Sensor
^ Oxygen Sensor
^ Throttle Position Sensor
^ Transaxle Control Module
^ Vehicle Speed Sensor
^ Volume Air Flow Sensor


ECM OUTPUTS
^ EVAP Purge Solenoid
^ Fuel Injectors
^ EGR Solenoiod
^ Idle Air Control Motor
^ Fuel Pressure Solenoid
^ Turbocharger Wastegate Solenoid
^ A/C Compressor Clutch Relay
^ Fuel Pump Relay
^ Ignition Coil
^ Malfunction Indicator Lamp
^ Heater Control



NOTE: Not all models use all inputs and outputs.