Back to results
US 9,316,131 B2Granted
Crankcase integrity breach detection
AssigneeFord Global Technologies, LLC
InventorsJohn Eric Rollinger, Robert Roy Jentz, Ross Dykstra Pursifull
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for using a crankcase vent tube pressure or flow sensor for diagnosing a location and nature of crankcase system integrity breach. The same sensor can also be used for diagnosing air filter plugging and PCV valve degradation. Use of an existing sensor to diagnose multiple engine components provides cost reduction and sensor compaction benefits.
Claims20
A method for an engine, comprising:
- during engine cranking, while manifold airflow is lower than a threshold, increasing intake throttle opening;
- and
- indicating crankcase ventilation system degradation based on a transient dip in crankcase vent tube pressure estimated by a sensor positioned within a crankcase vent tube following the intake throttle opening.
A method for an engine crankcase ventilation system, comprising:
- adjusting an actuator to raise an intake manifold vacuum to a threshold level;
- and
- while holding the vacuum at the threshold level via the actuator, indicating crankcase ventilation system degradation based on a transient dip in a crankcase vent tube pressure estimated by a pressure sensor positioned in a crankcase vent tube coupled between an intake manifold and a crankcase.
An engine crankcase ventilation system, comprising:
- an engine including an intake passage and a crankcase;
- a crankcase vent tube mechanically connected to the intake passage upstream of a compressor, the tube also mechanically connected to the crankcase via an oil separator, the vent tube located external to the engine;
- a sensor coupled in the crankcase vent tube for estimating a vent tube air flow;
- and
- a control system with computer readable instructions for,
- during engine cranking, when manifold airflow is lower than a threshold flow,
- adjusting an actuator to raise an intake manifold vacuum to a threshold level;
- and
- while holding the vacuum at the threshold level, indicating crankcase ventilation system degradation based on differences between an estimated flow rate and an expected flow rate through the crankcase vent tube.
6 more elements
Dependencies are inferred from the claim text.