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2010 Heavy Duty OBD Overview

2010 Heavy Duty OBD Overview. Marc Allain Detroit Diesel. Outline. OBD Requirements Overview Aftertreatment System Technical Challenges Summary. 2010 Heavy Duty OBD Requirements. Injection System Fuel Flow Pressure Timing Misfire. Major monitors Air system EGR system

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2010 Heavy Duty OBD Overview

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  1. 2010 Heavy Duty OBD Overview Marc Allain Detroit Diesel

  2. Outline • OBD Requirements Overview • Aftertreatment System • Technical Challenges • Summary

  3. 2010 Heavy Duty OBD Requirements • Injection System • Fuel Flow • Pressure • Timing • Misfire • Major monitors • Air system • EGR system • Injection system • Misfire • Cooling system • Crankcase ventilation • DOC • DPF • SCR • Rationality checks • Sensors • Actuators • Comprehensive component monitors • Circuit continuity checks Crankcase Ventilation • Cooling System • Thermostat Grid Heater • EGR System • EGR Valve • EGR Cooler • Air System • Turbocharger • Charge Cooler • SCR System • SCR Efficiency • Urea Doser • Urea Quality DOC DPF • DOC/DPF • Filtration Efficiency • Incomplete Regeneration • HC Doser • HC Slip SCR

  4. 2010 Heavy Duty OBD Requirements • OBD monitors must provide: • - Fault detection below OBD emissions thresholds • Monitoring frequency > legislated ratios

  5. Aftertreatment OBD – Major Monitors • SCR NOx conversion efficiency • DPF filtration efficiency • - NOx sensor malfunction • DOC HC conversion efficiency • - HC doser malfunction • - DEF doser malfunction • DEF quality • Major technical challenges • NOx sensor accuracy • Multiple vehicle applications • Fault separation • Threshold part development Good SCR Bad SCR SCR Efficiency Need sufficient separation to prevent false codes NOx (g/hp-hr) 0.2 0.6 OBD Threshold

  6. Aftertreatment OBD – Major Monitors DPF DP • SCR NOx conversion efficiency • DPF filtration efficiency • DOC HC conversion efficiency • HC doser malfunction • NOx sensor malfunction • DEF doser malfunction • DEF quality • Major technical challenges • Highly dynamic engine operation • - Threshold part development • Varying backpressure • 2013 Requirements • NO/NO2 ratio monitoring • Catalyzed DPF HC conversion efficiency Impacted by exhaust flow rate accuracy Good DPF Cracked DPF Exhaust flow rate Nominal Air system drift

  7. False Codes Threshold Parts False Passes Technical Risk Emission Threshold Monitoring Frequency Technical Challenges OBD monitors must provide: - Sufficient false code margin - Sufficient false pass margin • Test cell work • Calibration • Threshold part development • Emissions impact • - Steady-state conditions • - Transient cycle • - Hot/cold • - DPF regeneration • Vehicle validation • With faults in place • With nominal hardware • Loaded/bobtail • Hot/cold ambient • Aftermarket accessories • Offline validation • Statistical false code margin evaluation

  8. Summary • New OBD requirements being phased in starting in 2010 • Every engine system is impacted • OBD development challenges • - Low emission thresholds • - OBD-specific hardware required • - False code & false pass margin needed • - Extensive vehicle validation required • - Statistical evaluation of dozens of monitors • Additional legislated requirements starting in 2013 • - Lower OBD emission thresholds • - Higher performance ratios

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