# US 2017/0256103 A1 · Positive crankcase ventilation system diagnostic systems and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0256103 A1 - Document ID: US20170256103A1 - Status: Published application - Kind: A1 - Application number: 15/059,452 - Filed: 2016-03-03 - Published: 2017-09-07 - Earliest claimed: 2016-03-03 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Wenbo WANG; Layne K. WIGGINS; David R. KOSMALSKI - Web page: https://patentgrep.com/patent/US20170256103A1 ## CPC - G07C 5/0808: {Diagnosing performance data (testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005)} - B60W 10/00: Conjoint control of vehicle sub-units of different type or different function (for propulsion of purely electrically-propelled vehicles with power supplied within the vehicle B60L50/00 - B60L58/00) - F01M 11/10: Indicating devices; Other safety devices - F01M 13/00: Crankcase ventilating or breathing - 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)} - G07C 5/0816: {Indicating performance data, e.g. occurrence of a malfunction} - G07C 5/0841: {Registering performance data (recording measured values G01D; information storage G11B)} - F01M 2013/0083: {Crankcase pressure} - F02D 2200/025: Engine noise, e.g. determined by using an acoustic sensor - F02D 2250/08: Engine blow-by from crankcase chamber - Y02T 10/40: Engine management systems - 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 - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - F01M: LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING - 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) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A fault diagnostic system of a vehicle includes a noise module that determines a noise value based on a plurality of differences between samples of a pressure signal generated by a pressure sensor located in a positive crankcase ventilation (PCV) system of an engine. A signal module determines a signal value based on the samples of the pressure signal generated by the pressure sensor located in the PCV system of the engine. A diagnostic value module determines a diagnostic value based on one of: (i) a product of the noise value and the signal value; and (ii) a sum based on the noise value and the signal value. A fault module selectively diagnoses a fault in the PCV system based on the diagnostic value and generates a malfunction indicator within a passenger cabin of the vehicle in response to the diagnosis of the fault in the PCV system. ## Claims ### Claim 1 A fault diagnostic system of a vehicle, comprising: a noise module that determines a noise value based on a plurality of differences between samples of a pressure signal generated by a pressure sensor located in a positive crankcase ventilation (PCV) system of an engine; a signal module that determines a signal value based on the samples of the pressure signal generated by the pressure sensor located in the PCV system of the engine; a diagnostic value module that determines a diagnostic value based on one of: (i) a product of the noise value and the signal value; and (ii) a sum based on the noise value and the signal value; and a fault module that selectively diagnoses a fault in the PCV system based on the diagnostic value and that generates a malfunction indicator within a passenger cabin of the vehicle in response to the diagnosis of the fault in the PCV system. ### Claim 2 (depends on 1) The fault diagnostic system of claim 1 wherein the fault in the PCV system includes at least one of: one of a leak in the PCV system; and a disconnection of the PCV system from at least one of a crankcase of the engine and an air intake system of the engine. ### Claim 3 (depends on 1) The fault diagnostic system of claim 1 wherein the signal module sets the signal value based on an average of the samples of the pressure signal generated by the pressure sensor located in the PCV system. ### Claim 4 (depends on 1) The fault diagnostic system of claim 1 wherein the noise module sets the noise value based on an average of the differences between the samples of the pressure signal generated by the pressure sensor located in the PCV system. ### Claim 5 (depends on 1) The fault diagnostic system of claim 1 wherein the fault module diagnoses the fault in the PCV system when the diagnostic value is one of: greater than a first predetermined value; and less than a second predetermined value. ### Claim 6 (depends on 1) The fault diagnostic system of claim 1 further comprising a gain module that determines a gain value based on an average engine speed, wherein the diagnostic value module determines the diagnostic value based on a product of the noise value, the signal value, and the gain value. ### Claim 7 (depends on 1) The fault diagnostic system of claim 1 further comprising a gain module that determines a gain value based on an average engine speed, wherein the diagnostic value module determines the diagnostic value based on a sum of (i) the signal value and (ii) a product of the noise value and the gain value. ### Claim 8 (depends on 1) The fault diagnostic system of claim 1 wherein the noise module: determines squares of the differences between the samples of the pressure signal generated by the pressure sensor located in the PCV system; determines a second sum of the squares of the differences; and sets the noise value based on a square root of the second sum. ### Claim 9 (depends on 1) The fault diagnostic system of claim 1 wherein the noise module sets the noise value based on absolute values of the differences between the samples of the pressure signal generated by the pressure sensor located in the PCV system. ### Claim 10 (depends on 1) The fault diagnostic system of claim 1 wherein, in response to the diagnosis of the fault in the PCV system, the fault module further stores a diagnostic trouble code (DTC) in memory, the DTC being associated with the fault in the PCV system. ### Claim 11 A fault diagnostic method for a vehicle, comprising: determining a noise value based on a plurality of differences between samples of a pressure signal generated by a pressure sensor located in a positive crankcase ventilation (PCV) system of an engine; determining a signal value based on the samples of the pressure signal generated by the pressure sensor located in the PCV system of the engine; determining a diagnostic value based on one of: (i) a product of the noise value and the signal value; and (ii) a sum based on the noise value and the signal value; selectively diagnosing a fault in the PCV system based on the diagnostic value; and generating a malfunction indicator within a passenger cabin of the vehicle in response to the diagnosis of the fault in the PCV system. ### Claim 12 (depends on 11) The fault diagnostic method of claim 11 wherein the fault in the PCV system includes at least one of: one of a leak in the PCV system; and a disconnection of the PCV system from at least one of a crankcase of the engine and an air intake system of the engine. ### Claim 13 (depends on 11) The fault diagnostic method of claim 11 wherein setting the signal value includes setting the signal value based on an average of the samples of the pressure signal generated by the pressure sensor located in the PCV system. ### Claim 14 (depends on 11) The fault diagnostic method of claim 11 wherein setting the noise value includes setting the noise value based on an average of the differences between the samples of the pressure signal generated by the pressure sensor located in the PCV system. ### Claim 15 (depends on 11) The fault diagnostic method of claim 11 wherein diagnosing the fault in the PCV system includes diagnosing the fault in the PCV system when the diagnostic value is one of: greater than a first predetermined value; and less than a second predetermined value. ### Claim 16 (depends on 11) The fault diagnostic method of claim 11 further comprising: determining a gain value based on an average engine speed, wherein determining the diagnostic value includes determining the diagnostic value based on a product of the noise value, the signal value, and the gain value. ### Claim 17 (depends on 11) The fault diagnostic method of claim 11 further comprising: determining a gain value based on an average engine speed, wherein determining the diagnostic value includes determining the diagnostic value based on a sum of (i) the signal value and (ii) a product of the noise value and the gain value. ### Claim 18 (depends on 11) The fault diagnostic method of claim 11 wherein setting the noise value includes: determining squares of the differences between the samples of the pressure signal generated by the pressure sensor located in the PCV system; determining a second sum of the squares of the differences; and setting the noise value based on a square root of the second sum. ### Claim 19 (depends on 11) The fault diagnostic method of claim 11 wherein setting the noise value includes setting the noise value based on absolute values of the differences between the samples of the pressure signal generated by the pressure sensor located in the PCV system. ### Claim 20 (depends on 11) The fault diagnostic method of claim 11 further comprising, in response to the diagnosis of the fault in the PCV system, storing a diagnostic trouble code (DTC) in memory, the DTC being associated with the fault in the PCV system.