On-Board Diagnostics II (OBD II) and Emission Warranty Regulatory Update California Air Resources Board Mobile Source Control Division September 28, 2006.

  • Published on

  • View

  • Download


On-Board Diagnostics II (OBD II) and Emission Warranty Regulatory UpdateCalifornia Air Resources BoardMobile Source Control Division September 28, 2006Sacramento, CaliforniaTodays PresentationBackgroundGasoline OBDDiesel OBDOther ItemsBackgroundOBD II originally adopted 19891996 and newer vehiclesMonitors virtually every emission-related componentThreshold FunctionalIlluminates warning light and stores fault info for repair techniciansProgram updates occur regularlyLast revisions adopted April 2002Reasons for ChangesKeep pace with technologyI/M and technician feedback and experienceCertification staff experienceReview previous round of adopted requirementsWhere we are today120+ million OBD II equipped cars in the U.S.More than 50% of the in-use fleetOver 6 trillion miles accumulated in-use25 states in the U.S. using OBD II for I/M, including CANearly 13,000 OBD II inspections a day just in CATodays PresentationBackgroundGasoline OBDDiesel OBDOther ItemsGasoline OBD II OverviewRequirements very matureSystems largely performing as designedMinimal changes proposedUpdates focus primarily on issues identified in-useRear Oxygen Sensor MonitoringProblem: Not detecting some deteriorated catalystsCause: Inadequate rear O2 sensor performanceFix: Improved monitoring of rear O2 sensorProposal: 2009-2011 phase-inCylinder A/F ImbalanceProblem: Previously unconsidered failure mode with high emissionsCause: Cylinder to cylinder differences in air/fuel ratio E.g., fuel injector variationImproperly corrected by fuel controlFix: New monitor to specifically detect this fault using existing sensorsProposal: 2011-2014 phase-inCold Start EmissionsMost emissions occur at cold startBefore catalyst is warmed-upCold start strategies accelerate catalyst warm-upMonitoring currently required for failures that cause emissions to increase above a thresholdCold Start Strategy Monitoring Problem: Some only monitor entire strategyrequiring multiple components to fail before a fault is detectedFix: Require separate functional monitoring of each commanded elementE.g., ignition retardIndustry concern: Individual elements have small emission impact and cannot be monitored as stringently as proposedStaff Response: If any element is non-functional (e.g., no ignition retard), something obviously brokenTodays PresentationBackgroundGasoline OBDDiesel OBDOther ItemsDiesel OverviewFor Medium-duty, diesels:Majority of the fleetShare engines with Heavy-DutyAlign with Heavy-Duty OBD requirementsFor Light-duty, diesels:Currently Medium-Duty Threshold MonitorsFor 2010+, thresholds identical to heavy-dutyInterim levels in 2010, drop to final in 2013For 2007-2009, thresholds reflect currently available technologyExamples of threshold monitors include:PM filter, EGR, fuel system, etc.Light-Duty Threshold MonitorsGoal is to achieve gasoline OBD parity by 2013Less stringent requirements in 2007-2009 and 2010-2012Necessary to allow entry of diesels into the marketLD Diesel Threshold TableRED = 2007 thresholdLD Diesel Threshold TableRED = 2007 threshold YELLOW = 2010 thresholdLD Diesel Threshold TableBlue = 2013 thresholdSafeguards for Interim DieselsSome risk of excess emissions with reduced OBD capability in interimComponents degrade further before detectedSome unproven technologies (NOx catalyst)Additional in-use testing proposed to minimize riskVehicles tested at low and high mileageEnsure compliance with tailpipe standardsRecall and remedy if high in-use emissionsPursue including diesels in Smog CheckIssue: Stringency of Diesel ThresholdsIndustry:Proposed thresholds not feasible Workload too greatStaff Response:Thresholds feasible considering unexplored potential of latest monitoring strategies6 year phase-in of thresholds addresses workloadBackground: Adjustment FactorsPeriodic Regeneration EventsStored/trapped emissions purgedGenerally infrequentPerformed for several diesel components (e.g., PM filter)Create periods of higher emissionsAdjustment factors account for these emissionsAdded to normal driving emissions Gives a true average emission levelUsed to determine compliance (e.g., certification)Regeneration EmissionsAverage EmissionsIssue: Adjustment FactorsProposed Requirement: Calculate and use specific adjustment factors in determining OBD thresholdsIndustry Issue:Use of factors increases stringency of thresholdsWorkload too greatMust delay use of factors until 2010 or laterStaff Response:Necessary to ensure actual in-use emissions below malfunction thresholdsInterim flexibility proposed for early yearsUse factors already calculated for tailpipe standard prior to 2010Develop unique factor only for one monitor in 2008Unique factors for all monitors in 2010Background: Tracking of Emission Bypass StrategiesBypass strategiesReferred to as Emission Increasing-AECDsDesigned to avoid engine (or component) damage under specific conditionsIncrease emissions when activeDifficult for ARB to evaluate necessity and frequencyquantify emission impactNeed a means to validate manufacturer dataIssue: Tracking of Emission Bypass StrategiesRequirement: Track cumulative operation with bypass strategy invokedIndustry Issue:Does not belong in OBD II regulationBypass strategies highly confidentialTest program of a few vehicles would yield same dataStaff Response:Confidentiality not being compromisedData necessary to confirm minimal in-use activation (high emissions)Other ItemsConform OBD enforcement regulation to proposed changes in technical regulationRecall for specific noncompliances that affect SmogCheckEmission Warranty regulationsDelete obsolete warranty parts listSummaryEffective OBD is essential to assuring emissions remain lowAs important as the emission standards themselvesGasoline OBD working wellOnly minor changes neededDiesel OBD is newTime needed to develop highly effective OBDCan be achieved by 2013Staff Recommendation Adopt proposed regulations with 15 day changesNext technology review in 2 years


View more >