Powertrain Management: Description and Operation

PURPOSE
Modern engine management systems electronically regulate air/fuel mixture, idle speed, and ignition timing to achieve optimum [1] engine performance.

Since engine management is complex, it is helpful to divide information into sub-categories as explained below.

INFORMATION STRUCTURE
Engine Management Information is divided into four categories:

Computers and
Control Systems Addresses the on-board computer system and components as related to engine management. Consult this section for information regarding on-board diagnostics, sensor inputs, computer outputs, etc.

Emission Control
Systems Addresses emission related systems and components only. Includes (but is not limited to) Exhaust Gas Recirculation (EGR) systems, Evaporative Emission (EVAP) systems, Positive Crankcase Ventilation (PCV) systems, Exhaust Emission controls, Air Injection Systems (AIS), etc.

Fuel Supply and
Air Induction Focuses on systems and components related to fuel and intake air delivery. Does NOT include information regarding electronic engine controls.

Ignition System Focuses on primary and secondary ignition systems and components. Does NOT include information regarding electronic engine controls.

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[1] Optimum performance means the best possible compromise of the demands for high power, low fuel consumption, and clean exhaust emissions.