Systems and methods for cylinder exhaust 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 valve coupled to an engine cylinder. In one example, a method may include, routing compressed air from an electric booster into a cylinder with the intake valve of the cylinder open and the exhaust valve closed, and indicating degradation of the exhaust valve based on an exhaust airflow relative to a baseline airflow.
Claims20
A method, comprising:
- testing for degradation of an exhaust valve coupled to a cylinder of a multi cylinder engine, which drives a vehicle, by sealing the exhaust valve during an on-board test;
- routing compressed air into the cylinder during the test;
- and
- indicating presence or absence of degradation of the exhaust valve during the test based on an airflow through an exhaust coupled to the cylinders relative to a baseline airflow through the exhaust.
The method of 7, wherein the baseline airflow is established upon installation of the exhaust valve in the cylinder by routing compressed air through the cylinder with the intake valve open and the exhaust valve closed and estimating exhaust airflow via the differential pressure sensor.
An engine method, comprising:
- during a first condition, including an engine-off condition, forcing compressed air into a first cylinder of a multi cylinder engine while maintaining an intake valve of the first cylinder open and an exhaust valve of the first cylinder closed;
- and
- indicating degradation of the first cylinder responsive to a higher than threshold airflow through an exhaust coupled to the first cylinder.
A system, comprising:
- a vehicle, including an autonomous vehicle and/or a hybrid vehicle;
- an engine propelling the vehicle, the engine including a first cylinder, an intake passage, and an exhaust passage, the first cylinder including an intake valve and an exhaust valve, the intake valve actuated via an intake cam actuation system and the exhaust valve actuated via an exhaust cam actuation system;
- a conduit coupled to the intake passage downstream of a compressor and upstream of a CAC, the conduit including a motor-driven electric booster;
- a particulate filter coupled to the exhaust passage;
- a differential pressure sensor coupled across the particulate filter;
- and
- a controller with computer readable instructions stored on non-transitory memory for:
- during operation of the electric booster while the vehicle is in a keyed-off condition,
- commanding the intake cam actuation system and the exhaust cam actuation system to park the first cylinder in a first position with the intake valve open and the exhaust valve closed;
- sensing exhaust airflow in the exhaust passage via the differential pressure sensor after the commanded parking of the first cylinder;
- and
- indicating that the exhaust valve is leaking in response to the sensed exhaust airflow being higher than a threshold airflow.
Dependencies are inferred from the claim text.