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US 2019/0195153 A1Published application
Systems and methods for egr valve diagnostics
AssigneeFord Global Technologies, LLC
InventorAed M. Dudar
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for diagnosing degradation of an exhaust gas recirculation (EGR) valve. In one example, a method may include, during a vehicle key-off condition, routing compressed air through an EGR passage housing the EGR valve, and indicating degradation of the EGR valve based on a change in an estimated EGR pressure, upon a commanded change in EGR valve position.
Claims20
A method, comprising:
- while an engine is not combusting fuel, testing for degradation of an exhaust gas recirculation (EGR) valve coupled between an air intake and an exhaust of the engine;
- during the test, turning the EGR valve to at least one predetermined position and forcing compressed air into the EGR valve;
- and
- indicating presence or absence of the degradation based on one or more pressure readings across the EGR valve.
1 more element
A method comprising:
- in a first condition, closing an exhaust gas recirculation (EGR) valve positioned in an EGR passage, routing compressed air through the EGR passage, and indicating the EGR valve is stuck open responsive to a presence of pressure change in the EGR passage;
- and
- in a second condition, opening the EGR valve, routing compressed air through the EGR passage, and indicating the EGR valve is stuck closed in response to the absence of pressure change in the EGR passage.
A hybrid vehicle system, comprising:
- a vehicle;
- an engine including one or more cylinders, an intake manifold, and an exhaust manifold;
- an intake passage including a compressor and a charge air cooler (CAC) downstream of the compressor;
- a conduit coupled to the intake passage downstream of the compressor and upstream of the CAC, the conduit including a motor-driven electric booster;
- an electric booster bypass valve coupled at a junction of the intake passage and the conduit;
- an exhaust gas recirculation (EGR) passage coupling the exhaust manifold to the intake manifold, downstream of the compressor, the EGR passage including an EGR valve and an orifice;
- a differential pressure sensor coupled across the orifice in the EGR passage;
- and
- a controller with computer readable instructions stored on non-transitory memory for:
- while operating the electric booster during a vehicle key-off condition,
- commanding the EGR valve to a completely closed position;
- sensing EGR pressure via the differential pressure sensor after the commanded closing of the EGR valve;
- and
- indicating that the EGR valve is stuck at an open position in response to the sensed EGR pressure being higher than a first threshold pressure.
11 more elements
Dependencies are inferred from the claim text.