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US 2026/0168456 A1Published application
Methods and systems for diagnosing four oxygen sensor system
AssigneeFord Global Technologies, LLC
InventorsRani Kiwan, Yusef Sadat-Hossieny, Chris Paul Glugla, Kenneth John Behr, Michael Uhrich
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Abstract
Systems and methods for evaluating operation of a plurality of upstream and downstream oxygen sensors are disclosed. In one example, the air to fuel patterns may be arranged in an order to reduce an amount of time it takes to evaluate upstream and downstream oxygen sensors. The oxygen sensor evaluation may be suitable to detect sensor miswiring and sensor degradation.
Claims20
A method for operating an engine, comprising:
- commanding each of two groups of fuel injectors to generate one of a stoichiometric, rich, or lean air-fuel ratio in each of two pairs of cylinders and to generate at least four different cylinder air-fuel ratio patterns in the two pairs of cylinders during at least four different time intervals of an oxygen sensor diagnostic.
An engine system, comprising:
- an internal combustion engine comprising a first bank of cylinders and a second bank of cylinders, and at least eight fuel injectors including at least one fuel injector for each cylinder of the first bank of cylinders and at least one fuel injector for each cylinder of the second bank;
- a first oxygen sensor configured to sense gases exhausted from first and second cylinders of the first bank of cylinders;
- a second oxygen sensor configured to sense gases exhausted from third and fourth cylinders of the first bank of cylinders;
- a third oxygen sensor configured to sense gases exhausted from fifth and sixth cylinders of the second bank of cylinders;
- a fourth oxygen sensor configured to sense gases exhausted from seventh and eighth cylinders of the second bank of cylinders;
- a controller including executable instructions stored in non-transitory memory that cause the controller to command the at least eight fuel injectors to generate one of a stoichiometric, rich, or lean air-fuel ratio in each cylinder of the first bank of cylinders and each cylinder of the second bank and to generate at least four different cylinder air-fuel ratio patterns in the first bank of cylinders and the second bank of cylinders during at least four different time intervals of an oxygen sensor diagnostic sequence.
3 more elements
A method for operating an engine, comprising:
- commanding a maximum of one rich to lean, or one lean to rich, air-fuel ratio change in a pair of engine cylinders during an oxygen sensor diagnostic sequence that is a basis for determining miswiring of four upstream oxygen sensors and comparing outputs of the four upstream oxygen sensors to air-fuel ratio changes performed during the oxygen sensor diagnostic sequence.
Dependencies are inferred from the claim text.