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US 7,007,458 B2Granted
Vehicle having an emission control device diagnostic computer
AssigneeFord Global Technologies, LLC
InventorsChristopher John Mazur, Michael Leonard Corsetti
Life of this patent
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Abstract
A computer controlled diagnostic system is described that monitors catalyst activity of an upstream catalyst using a sensor located downstream of a downstream catalyst. In this way, a system configuration is achieved that allows for diagnosis as well as improved air-fuel ratio control.
Claims17
A computer-controlled emission diagnostic system for an engine exhaust system of a vehicle, comprising:
- a first emission control device coupled to an exhaust of the engine;
- a second emission control device coupled downstream of said first emission control device;
- a first exhaust gas sensor coupled upstream of said first emission control device;
- a second exhaust gas sensor coupled in or downstream of said second emission control device;
- a computer storage medium having a computer program encoded therein for monitoring the engine exhaust system comprising:
- code for reading a fist signal from said first exhaust gas sensor,
- code for reading a second signal from said second exhaust gas sensor;
- code for indicating an interval in which said first emission control device is operating with an oxygen storage capacity above a preselected percentage based on an estimated catalyst temperature of said first emission control device and said second emission control device is operating with an oxygen storage capacity below a predetermined percentage based on an estimated catalyst temperature of said second emission control device;
- and
- code for determining performance of said first emission control device based at least on said first and second signals during said indicated interval.
7 more elements
An emission control system for an engine of a vehicle, comprising:
- a first emission control device coupled to an exhaust of the engine;
- a second emission control device coupled downstream of said first emission control device;
- a first exhaust gas sensor coupled upstream of said first emission control device;
- a second exhaust gas sensor coupled in or downstream of said second emission control device;
- a controller for reading a first signal from said first exhaust gas sensor, reading a second signal from said second exhaust gas sensor;
- determining a period in which said first emission control device is operating above a preselected percentage of oxygen storage capacity based on estimated temperature of said first emission control device, and said second emission control device is operating below a preselected percentage of oxygen storage capacity based on estimated temperature of said second emission control device;
- and during said period, determining performance of said first emission control device based at least on said first and second signals.
4 more elements
An emission control system for an engine of a vehicle, comprising:
- a first emission control device coupled to an exhaust of the engine in a close coupled location;
- a second emission control device coupled downstream of said first emission control device in an underbody location;
- a first exhaust gas sensor coupled upstream of said first emission control device;
- a second exhaust gas sensor coupled in or downstream of said second emission control device;
- a controller for reading a first signal from said first exhaust gas sensor, reading a second signal from said second exhaust gas sensor;
- determining an interval in which said first emission control device is operating above a preselected percentage of oxygen storage capacity based on estimated temperature of said first emission control device and said second emission control device is operating below a preselected percentage of oxygen storage capacity based on estimated temperature of said second emission control device;
- and during said interval, determining performance of said first emission control device based at least on said first and second signals.
4 more elements
Dependencies are inferred from the claim text.