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.


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