CRANKCASE INTEGRITY BREACH DETECTION
First Claim
Patent Images
1. A method for an engine, comprising:
- during engine cranking, while manifold airflow is lower than a threshold,increasing throttle opening; and
indicating crankcase ventilation system degradation based on a change in crankcase vent tube pressure following the throttle opening.
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Accused Products
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.
46 Citations
20 Claims
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1. A method for an engine, comprising:
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during engine cranking, while manifold airflow is lower than a threshold, increasing throttle opening; and indicating crankcase ventilation system degradation based on a change in crankcase vent tube pressure following the throttle opening. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for an engine crankcase ventilation system, comprising:
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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 transient dip in a crankcase vent tube pressure. - View Dependent Claims (12, 13, 14, 15, 16)
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17. An engine crankcase ventilation system, comprising:
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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. - View Dependent Claims (18, 19, 20)
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Specification