# US 10,767,590 B1 · Crankcase ventilation system and diagnostic method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,590 B1 - Document ID: US10767590B1 - Status: Granted - Kind: B1 - Application number: 16/450,861 - Filed: 2019-06-24 - Granted: 2020-09-08 - Earliest claimed: 2019-06-24 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Robert Roy Jentz; Matthew Carpenter; Michael Stephen Sweppy - Web page: https://patentgrep.com/patent/US10767590B1 ## CPC - F02D 41/22: Safety or indicating devices for abnormal conditions {(in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809)} - F01M 13/021: {of negative pressure} - F01M 13/04: having means for purifying air before leaving crankcase, e.g. removing oil - F02B 37/12: Control of the pumps - F02D 41/0007: {for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12)} - G07C 5/0808: {Diagnosing performance data (testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005)} - G07C 5/0816: {Indicating performance data, e.g. occurrence of a malfunction} - F01M 2013/0038: {Layout of crankcase breathing systems} - F01M 2013/005: {having one or more deoilers} - F01M 2013/0083: {Crankcase pressure} - F01M 2013/027: {with a turbo charger or compressor} - F02D 2041/228: {Warning displays} - F02D 2200/0406: Intake manifold pressure - F02D 2250/08: Engine blow-by from crankcase chamber - Y02T 10/12: Improving ICE efficiencies - Y02T 10/40: Engine management systems - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F01M: LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Methods and systems are provided for diagnosing a positive crankcase ventilation (PCV) system. In one example, a diagnostic method for a PCV system is provided that includes, when an intake manifold air pressure is above a threshold boost value, determining a PCV system breach based on a pressure determined using a pressure sensor positioned on a clean side of an oil separator coupled to a crankcase and receiving crankcase gas from the crankcase. In the PCV system a ventilation line provides fluidic communication between the oil separator and an intake conduit upstream of a compressor. ## Claims ### Claim 1 A method comprising: when an intake manifold air pressure is above a threshold boost value, determining a positive crankcase ventilation (PCV) system breach based on a pressure determined using a pressure sensor positioned on a clean side of an oil separator coupled to a crankcase and receiving crankcase gas from the crankcase, where a ventilation line provides fluidic communication between the oil separator and an intake conduit upstream of a compressor. ### Claim 2 (depends on 1) The method of claim 1, where determining the PCV system breach includes determining the ventilation line is leaking and/or disconnected from the oil separator and/or the intake conduit. ### Claim 3 (depends on 1) The method of claim 1, where determining the PCV system breach includes determining if the pressure of the pressure sensor is greater than a fault threshold and where the fault threshold is a determined based on barometric pressure in the intake manifold and/or ambient temperature. ### Claim 4 (depends on 1) The method of claim 1, where determining the PCV system breach includes sampling the pressure sensor. ### Claim 5 (depends on 4) The method of claim 4, where a length of the sampling of the pressure sensor is determined based on a crankcase pressure and/or a pressure in the intake manifold. ### Claim 6 (depends on 4) The method of claim 4, where a length of the sampling of the pressure sensor is determined based a pressure in the intake conduit upstream of the compressor. ### Claim 7 (depends on 1) The method of claim 1, further comprising, responsive to determining the PCV system breach, implementing a mitigating action, where the mitigating action includes adjusting boost generated by the compressor. ### Claim 8 (depends on 1) The method of claim 1, further comprising: responsive to determining the PCV system breach, setting a diagnostic code indicating PCV system breach; and/or notifying a vehicle operator of the PCV system breach. ### Claim 9 A positive crankcase ventilation (PCV) system comprising: a crankcase including an interior chamber; an oil separator coupled to the crankcase; a PCV valve positioned in a PCV line coupled to the crankcase and an intake manifold downstream of a compressor; a ventilation line coupled to the oil separator and an intake conduit located upstream of the compressor; a pressure sensor positioned on a clean side of an oil separator and spaced away from an end of the ventilation line, the oil separator coupled to the crankcase; and a controller including instructions stored in non-transitory memory that when executed cause the controller to: while the PCV system is operated with a boosted engine condition where an intake manifold air pressure is above a threshold value and where a PCV valve in a PCV line coupled to a crankcase and an intake manifold downstream of a compressor meters gas flow to the crankcase, determine a PCV system breach based on a pressure determined using the pressure sensor. ### Claim 10 (depends on 9) The PCV system of claim 9, where the PCV valve is a passive bi-directional valve including a metering orifice. ### Claim 11 (depends on 10) The PCV system of claim 10, where the metering orifice is in parallel fluidic communication with a check valve. ### Claim 12 (depends on 9) The PCV system of claim 9, where the oil separator and the pressure sensor are located in a cam cover. ### Claim 13 (depends on 9) The PCV system of claim 9, where determining the PCV system breach includes determining the ventilation line is disconnected from the oil separator and/or the intake conduit and where determining the PCV system breach includes determining if the pressure determined using the pressure sensor is greater than a fault threshold and where the fault threshold is determined based on barometric pressure and/or ambient temperature. ### Claim 14 (depends on 9) The PCV system of claim 9, where determining the PCV system breach includes sampling the pressure sensor and where a length of the sampling of the pressure sensor is determined based on: a crankcase pressure and/or a pressure in the intake manifold; or a pressure in the intake conduit upstream of the compressor. ### Claim 15 (depends on 9) The PCV system of claim 9, where the controller includes instructions stored in the non-transitory memory that when executed cause the controller to sample the pressure sensor during a time period including multiple boost events and/or drive cycles. ### Claim 16 (depends on 9) The PCV system of claim 9, where the controller includes instructions stored in the non-transitory memory that when executed cause the controller to: implement a mitigating action in response to determining the PCV system breach, where the mitigating action includes adjusting boost generated by the compressor. ### Claim 17 A diagnostic method for a positive crankcase ventilation (PCV) system, comprising: operating the PCV system with a boosted engine condition where an intake manifold air pressure is above a threshold value and where a PCV valve in a PCV line coupled to a crankcase and an intake manifold downstream of a compressor meters gas flow to the crankcase; and while the PCV system is operated with the boosted engine condition, determining a PCV system breach based on a pressure measured using a pressure sensor arranged on a clean side of an oil separator coupled to the crankcase, where the sensor spaced away from an end of a ventilation line coupled to the oil separator and an intake conduit upstream of the compressor; and responsive to determining the PCV system breach, setting a diagnostic code indicating PCV system breach, notifying a vehicle operator of the PCV system breach, and/or implementing a mitigating action. ### Claim 18 (depends on 17) The diagnostic method of claim 17, where determining the PCV system breach includes sampling the pressure sensor and where a length of the sampling of the pressure sensor is determined based on: a crankcase pressure and/or a pressure in the intake manifold; or a pressure in the intake conduit upstream of the compressor. ### Claim 19 (depends on 17) The diagnostic method of claim 17, where the mitigating action includes adjusting boost generated by the compressor. ### Claim 20 (depends on 17) The diagnostic method of claim 17, where the PCV valve is a passive bi-directional valve including a metering orifice and where the pressure sensor and the oil separator are positioned in a cam cover.