Introduction to On Board Diagnostics (II)

Powertrain and EmissionControls in PassengerVehiclesAn Overview:On-line diagnosis of internal combustion engines in passenger vehiclesis mandated due to the strict environmental regulations in the U.S.A Uand in some European countries (e.g.., the EFTA (European Free TradeTAgency) partners) to control Hydro carbon emissions from the exhaust.Powertrain subsystem consists of the engine and transmission including theexhaust emission control apparatus which needs to be continuouslymonitored by the engine controller (computer) for potential defectsleading to decreased effectiveness in emission control system (e.g., three-waycatalyst) resulting in increased emission of hydrocarbons which are regulatedby the EPA.