Powertrain Management: Description and Operation

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

INFORMATION STRUCTURE
Information in Computer, Fuel, Ignition and Emission Systems is divided into the following four major topics:

Computerized Engine Controls
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 Controls
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 Systems
Focuses on systems and components related to fuel and intake air delivery. Does NOT include information regarding electronic engine controls.

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

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