The Diesel Particulate Filter System With Additive - WordPress
Service TrainingSelf-study programme 330The diesel particulate filter systemwith additiveDesign and Function
Combustion will remain in the foreseeable future animportant method of energy conversion, whether inpower stations, cars – or even fireplaces.These aspects and strict emissions legislation have ledengineers to place particular emphasis on the continual reduction of particulate emissions.Every fire leaves behind harmful by-products ofcombustion - particles of soot for example.One way to reduce the emission of carbon soot is witha diesel particulate filter.The aim is to avoid risks to the environment and healthcaused by the generation and release of carbon soot.S330 001Further information on the subject of exhaust gas can be found in the following self-study programmes: SSP 124: Diesel engine with catalytic converter SSP 230: Vehicle exhaust emissions SSP 315: European onboard diagnosis for diesel enginesNEWThe self-study programme represents the designand function of new developments!The contents will not be updated.2For current testing, adjustment and repair instructions, refer to the relevant service literature.CautionNote
ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Design and function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12System overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Sensors and actuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Functional diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31System limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33Test yourself. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
IntroductionGeneralDuring combustion of diesel fuel, all sorts of differentdeposits are built up. Those that can be perceiveddirectly as emissions components on a cold engineare non or partly oxidised hydrocarbons in dropletform as white or blue smoke and strong smellingaldehyde.In addition to harmful gaseous substances, particlesof solid substances are emitted with the emissionsfrom diesel engines, which have been included underthe main heading of particulates with regards tosubstances that are damaging to health and theenvironment.S330 035Volkswagen follows a long-term strategy with the aimof reducing exhaust emissions – not only in the areaof diesel particulates but also for all other emissionscomponents, such as hydrocarbons and nitrogenoxides. Some years ago, Volkswagen undertook toughmeasures on a continual basis to optimise the internalcombustion processes and to reduce the emission ofcarbon soot particles from diesel engines. And withsuccess: In 1999, Volkswagen was able to offer theLupo 3L TDI on the market as the first vehicle to meetthe strict Euro 4 exhaust emissions standard – sixyears before the standard was established as a legalrequirement in 2005.4Volkswagen played an important role in driving onthe development for clean diesel fuel and therebyfaced the responsibility of protecting the environment.Examples of this are the efficient, economical and lownoise generating TDI technology and also the unitinjector system. Volkswagen will continue to selectivelyimprove internal combustion processes in the future tofurther bring down fuel consumption and reduceemissions directly at source. In addition, Volkswagenwill enhance these efforts step-by-step by theintroduction of diesel particulate filter systems.
The exhaust gasEmissions standardsIn the Republic of Germany, across Europe and throughout the world, laws have been passed in recent years toreduce the emission of harmful substances in the air. In Europe, the emissions standards are categorised from EU1to EU4. These prescribe emission limits to the automobile industry for type approval of new vehicle models.EU3EU4As of the year 2000, EU3 is the emissions standardfor new vehicle registrations.The EU4 standard will come into force in 2005 andwill supersede EU3. The consequences are a furtherreduction in permissible limit values.It differs from its predecessor EU2 by more stringentconditions on the test bed and by a reduction in thelimit values.Even now, more than 65 percent of all Volkswagenswith diesel engines newly registered in Germany fulfilemissions standard EU4.Permissible limit values for diesel EU4COCarbon monoxideEU3EU4HC NOXHydrocarbons andnitrogen oxidesEU3EU40,050,025EU3EU4NOXPMNitrogen oxidesSoot particlesS330 026OutlookIn the future, the more stringent EU5 standard will come into force. The limit values for this standard have as yet notbeen established, but acceptable emission levels will be lowered even further. There are plans to markedly reducethe particulate limit value for diesel passenger vehicles even further. Therefore, all diesel passenger vehicles mustbe fitted with a particulate filter in the future.5
IntroductionHarmful substances caused by combustionThe harmful substances, and particulate emissions in particular, are influenced in a diesel engine by thecombustion process. This process is affected by many factors relating to the construction, the fuel itself and theatmosphere.The following illustration shows an overview of the inlet and exhaust components of a diesel engine duringcombustion.Injected fuel:HC HydrocarbonsSSulphurapprox. 12%SO2CO2N2approx.11%H2OO2Intake air:O2 OxygenN2 CNOXCOapprox. 67%S330 108Exhaust gas:O2 OxygenN2 NitrogenH2O WaterCO2 Carbon dioxideCOHCSO2NOxPMCarbon monoxideHydrocarbonsSulphur dioxideNitrogen oxideCarbon soot particles(PM particulate matter)With regards to the damaging effect on theenvironment and health, the emissions from a dieselengine have various components that requiredifferent analyses.Those components that are already present in theatmosphere (oxygen, nitrogen and water) can becategorised as safe.6Carbon dioxide, which is present in the atmosphere asa natural gas, is at the limit between safe and harmfuldue to its categorisation. It may not be poisonous, butin higher concentrations it can contribute towards thegreenhouse effect.Carbon monoxide, hydrocarbons, sulphur dioxide,nitrogen oxide and particulates are categorised asharmful.
Harmful substances in the exhaust gasCarbon monoxide (CO) is generated from oxygendeficiency as a result of the incomplete combustion offuels containing carbon. It is a gas and has no colour,smell or taste.COCarbonmonoxideS330 014Hydrocarbons cover a wide range of differentcompounds (for example C6H6, C8H18), which occuras a result of incomplete combustion.HCHydrocarbonsS330 016Sulphur dioxide is generated by the combustion offuel containing sulphur. It is a gas without colour butwith a pungent smell. The amount of sulphur added tofuel is decreasing.SO2Sulphur dioxideS330 018Nitrogen oxides (for example NO, NO2, . . .)are generated by high pressure, high temperatureand excessive oxygen during combustion in theengine.NOxNitrogen oxidesS330 020If there is an oxygen deficiency the result is a build upof carbon soot particles from incomplete combustion.Soot particlesS330 0227
IntroductionThe particulatesParticulates is a term that covers all particles, solid orliquid, that are generated from friction, breakdown ofcomponents, erosion, condensation and incompletecombustion. These processes create particulates indifferent shapes, sizes and structures.Particulates have the same character as harmfulsubstances in the air if, due to their small dimensions,they can float around in gaseous substances anddamage organisms.Soot particlesSome hydrocarbon compounds are categorised aspotentially hazardous to health.The exact composition of soot particles depends onthe engine technology, the conditions of use and thetype of fuel.Soot particles are generated from the combustionprocess in a diesel engine. Soot particles aremicroscopic balls of carbon with a diameter of about0.05 µm. Their core consists of pure carbon.Around the core are deposits of differenthydrocarbon compounds, metal oxides and sulphur.SO4 (sulphate)HydrocarbonsSulphur and metal oxidesCarbonH2O (water)S330 1828
Cause of soot particlesThe build up of soot particles in a diesel engine depends on the individual processes of diesel combustion, such asair intake, injection, flame spread.The combustion quality depends on how well the fuel is mixed with the air.The mixture in some areas of the combustion chamber could be too rich because not enough oxygen is present.Combustion will then be incomplete and soot particles will be formed.S330 013The mass and number of particles are thereforeaffected in essence by the quality of the enginecombustion process. With high injection pressure andan injection pattern based on the requirements of theengine, the unit injector system ensures efficientcombustion and thereby reduces the formation of sootparticles during the combustion process.High injection pressure and associated fineatomisation of the fuel, however, does not necessarilylead to smaller particles.Tests have shown that the difference in particle sizes inthe exhaust gas is very similar regardless of thecombustion principle of the engine, whether swirlchamber, common rail or unit injector technology.Typical particle of soot caused from dieselengine combustion9
IntroductionThe measures to reduce particulatesThe reduction of exhaust emissions in a diesel engine is an important aim in further development.To reduce exhaust emissions there is a series of different technical solutions.Here, a difference is made between internal and external engine measures.Internal engine measuresA reduction in emissions can be achieved bymeasures to the internal workings of an engine.Effective optimisation of the combustion process canensure that harmful substances are not producedat all.Examples of internal engine measures are:S330 04510 the design of the inlet and exhaust ports foroptimal flow properties, high injection pressures by means of unit injectortechnology, the combustion chamber design, for examplereduction in the size of the area where harmfulsubstances are produced, design of the pistoncrown.
External engine measuresThe release of soot particles that are produced during combustion can be prevented by external engine measures.This can be seen as the reduction of soot particles by means of a particulate filter system.To do this, it is necessary to differentiate between two systems – the diesel particulate filter with additive and thediesel particulate filter without additive. Explained on the following pages is exclusively the design and function ofthe diesel particulate filter systems with additive, currently used by Volkswagen.System with additiveThis system is used on vehicles where the particulate filter is installed away from the engine. Due to the distance theexhaust gas has to make from the engine to the particulate filter, the required ignition temperature for combustionof the particulates can only be reached with the introduction of an additive.Temperature of exhaust gas in thisarea at part-throttle750 COxidising catalytic converter620 CParticulate filter500 CS330 142System without additiveThis system will be installed in the future on vehicles with particulate filters close to the engine. Due to the shortdistance exhaust gas has to take from the engine to the particulate filter, the temperature of the exhaust gas issufficiently high enough to burn off the carbon soot particles.Temperature of exhaust gas in thisarea at part-throttle750 CParticulate filter with integratedoxidising catalytic converter620 CS330 14411
Design and functionThe diesel particulate filter system with additiveShown in the overview below are the components of the diesel particulate filter system. The design and function ofthe diesel particulate filter system with additive are explained on the following pages.16325741614891013111215S330 03012345678Control unit in dash panel insert J285Engine control unitAdditive tankFuel additive tank empty sender G504Particulate filter additive pump V135Fuel tankDiesel engineTemperature sender before turbocharger G507910111213141516TurbochargerLambda probe G39Oxidising catalytic converterTemperature sender before particulate filter G506Particulate filterExhaust gas pressure sensor 1 G450SilencerAir mass meterThe overview shows a system with single exhaust pipe. In the event of twin or multi exhaust systems(for example on the V10 TDI engine), the particulate filter and exhaust gas sensors are fitted to eachline of the exhaust system.12
The particulate filterThe diesel particulate filter (for example on the Passatwith 2.0 ltr. TDI engine) can be found in the exhaustpipe after the oxidising catalytic converter.It filters particles of carbon out of theexhaust gas of the engine.S330 017DesignThe diesel particulate filter comprises of a honeycombceramic matrix made from silicon carbide, which canbe found in a metal housing. The ceramic matrix itselfhas many microscopic channels that run parallel andare alternately connected to each other.Silicon carbide is a suitable filteringmaterial due to the following properties: High mechanical strength Very good resistance to thermal changes Thermal resilience and conductivity High resistance to wearHoneycombceramic matrixS330 038S330 154FunctionWhen exhaust gas enters the filter, particles of carbon are trapped in the input channels, while the gaseous contentof the exhaust gas flows through the porous walls of the ceramic filter.13
Design and functionRegenerationThe diesel particulate filter must be cleaned of theparticles of regularly to prevent it from becomingblokked and its function thereby being affected.During the regeneration phase, the particles ofcarbon stored in the filter are burnt off at atemperature of approx. 500 C. The actual ignitiontemperature of the particulates is about 600-650 C.This exhaust gas temperature can only be reached ona diesel engine at full throttle.In order to ensure regeneration of the diesel particulate filter under all operating conditions, the ignitiontemperature of the carbon is lowered by theintroduction of an additive, and the exhaust gastemperature is raised by the engine managementsystem.The regeneration procedure is initiated by the enginecontrol unit.Particulate filter emptySignals toengine control unitAir mass meter G70Temperature senderbefore particulate filter G506Exhaust gas pressure sensor 1G450S330 042Particulate filter empty low resistance to flowParticulate filter fullSignals toengine control unitAir mass meter G70Temperature senderbefore particulate filter G506Exhaust gas pressure sensor 1G450S330 044Particulate filter full high resistance to flow14
During regeneration, the tiny particles of carbonstored in the particulate filter are burnt off.This occurs every 500-700 kilometres, depending onthe way the vehicle is driven, and lasts about 5-10minutes. There are no signs to the driver thatregeneration is occurring.Regeneration of the particulate filterSignals toengine control unitAir mass meter G70Exhaust gas pressure sensor 1G450Temperature sender beforeparticulate filter G506S330 05115
Design and functionThe additiveThe additive is an iron-rich substance, which isdissolved in a hydrocarbon mixture.It can be found on the Passat in a separate fuel tankin the spare wheel well.S330 112Additive tankThe additive has the task of lowering the temperatureat which the carbon particles burn, in order to allowregeneration of the particulate filter even atpart-throttle.The ignition temperature of the particulatesis about 600-650 C. Exhaust gas temperatures at thislevel are only achieved on diesel engines at fullthrottle. By introducing the additive, the ignitiontemperature of the carbon particles is reduced toapprox. 500 C.The additive is mixed automatically with the fuel in thetank via the fuel return line each time the fuel tank isreplenished. This occurs by means of a particulatefilter additive pump, which is actuatedby the engine control unit.The amount of fuel replenished is determined by theengine control unit, which draws information from thefuel tank sender. Each time additive is added to thefuel tank, the concentration of iron molecules inthe fuel is 10 ppm (parts per million).This equates to an approximate ratio of 1 litreof additive to 2800 litres of fuel.AdditiveCarbon particlesThe additive in the fuel finds its way into theparticulate filter together with the carbon soot. Itbuilds up here as a deposit between the particles ofsoot.S330 18616
Level of carbon deposit in particulate filterThe level of carbon deposit in the particulate filter is constantly monitored by the engine control unit, whichcalculates the flow resistance of the filter. To determine the flow resistance, the exhaust gas volume before theparticulate filter is compared with the pressure difference before and after the particulate filter and recorded as aratio.Pressure differenceThe pressure difference of the air flow before and after the particulate filter is calculated by exhaust gas pressuresensor 1.Exhaust gas volumeThe exhaust gas volume is calculated by the engine control unit from the air mass in the exhaust manifoldand the exhaust gas temperature before the particulate filter. The mass of exhaust gas is roughly equivalent to themass of air in the intake manifold, which is calculated by the air mass meter. The volume of exhaust gas dependson the respective temperature. This is calculated by the temperature sender before particulate filter.Using the exhaust gas temperature reading, the engine control unit can calculate the exhaust gas volume from themass of air in the exhaust gas.Flow resistance of particulate filterPressure difference p (mbar)3002502001501005000100200300400500600700S330 1563Volume (m /h)Diesel particulate filter:fullemptydefectiveThe engine control unit creates a ratio from the pressure difference and the volume of exhaust gas and can thuscalculate the flow resistance of the particulate filter. From the flow resistance, the engine control unit can detect thelevel of carbon deposit.17
Engine management during regenerationFrom the flow resistance of the filter, the engine control unit can detect the level of carbon deposit in the filter.A high flow resistance indicates that the filter is in danger of becoming blocked. The engine control unit initiatesregeneration. To do this: exhaust gas recirculation is switched off toraise the combustion temperature,S330 124 an extended injection period is initiated, after aperiod of main injection with reduced quantity at35 crankshaft angle after TDC, in order to increasethe exhaust gas temperature,S330 126 the supply of intake air is regulated by anelectric throttle valve andS330 120 the charge air pressure is adapted so thatthe torque during regeneration does not changenoticeably by the driver.S330 12218
System overviewSystem overview of diesel particulate filter with additiveCAN busControl unit in dash panel insert J285Exhaust gas pressure sensor 1G450Diesel particulate filterwarning lamp K231Preglow controllamp K29Temperature sender beforeparticulate filter G506Temperature sender beforeturbocharger G507Particulate filter additive pump V135Diesel direct injection systemcontrol unit J248Lambda probe G39Lambda probe heater Z19Air mass meter G70Diagnosis connectorUnit injector valves N240-N243Fuel additive empty sender G504Solenoid valve block with:Exhaust gas recirculation valve N18Charge pressure control solenoid valve N75S330 106Fuel gauge sender GIntake manifold flap motor V15719
Sensors and actuatorsThe sensorsExhaust gas pressure sensor 1 G450Exhaust gas pressure sensor 1 uses piezo technology.Signal applicationExhaust gas pressure sensor 1 measures the pressuredifference in the flow of exhaust gas before and afterthe particulate filter. The signal from the exhaust gaspressure sensor, the signal from the temperaturesender before particulate filter and the signal fromthe air mass meter form an inseparable unit duringcalculation of the level of carbon soot deposit in theparticulate filter.S330 048Effects of signal failureIn the event of signal failure from the exhaust gaspressure sensor, the particulate filter regenerationcycle will be based on the distance travelled or thenumber of hours of operation. This cycle forparticulate filter regeneration, however, is noteffective over a long period of time.After a predetermined number of cycles, the dieselparticulate filter warning lamp will light up and thenthe preglow control lamp will flash in the dash panelinsert. This informs the driver that the vehicle must bedriven to a workshop.DesignExhaust gas pressure sensor 1 features two pressureconnections. Leading from one is a pressure line to theflow of exhaust gas before particulate filter and fromthe other to the flow of exhaust gas after particulatefilter.Membrane with piezoelementsSignal tocontrol unitInstalled in the sender is a membrane with piezoelements, which effect the respective exhaust gaspressures.S330 050Pressure beforefilter20Pressure afterfilter
This is how it works:Particulate filter emptyS330 090If the particulate filter has a very low carbon sootdeposit level, the pressure before and after the filter isalmost the same.The membrane with the piezo elements is in the restposition.Piezo elementsS330 160Pressure before filter pressure afterfilterParticulate filter fullS330 092S330 162Pressure before filter pressure afterfilterIf there is a build up of carbon soot in the particulatefilter, the exhaust gas pressure rises before the filterdue to a lower flow volume.The exhaust gas pressure behind the filter remainsalmost the same. The membrane changes its shapedepending on the difference in pressure.This deformation alters the electrical resistance of thepiezo elements, which are connected to form a testbridge. The output voltage of this test bridge isprocessed, amplified and sent by the sensorelectronics as a signal voltage to the engine controlunit. From this signal, the engine control unitcalculates the level of carbon soot deposit in theparticulate filter and initiates regeneration to cleanthe filter.The level of carbon soot deposit in the particulate filter can be checked using vehicle diagnosis,testing and information system VAS 5051 as a "particulate charge coefficient" in a measured valueblock.21
Sensors and actuatorsTemperature sender before particulate filter G506S330 100S330 114The temperature sender before particulate filter is aPTC sensor. On a sensor with PTC (positivetemperature coefficient), resistance rises astemperature increases.It can be found in the exhaust system before the dieselparticulate filter. There it measures the temperature ofthe exhaust gas.Signal applicationEffects of signal failureUsing the signal from the temperature sender beforeparticulate filter, the engine control unit calculates theexhaust gas volume in order to determine the level ofcarbon soot deposit in the particulate filter.In the event of signal failure from the temperaturesender before particulate filter, the particulate filterregeneration cycle will be based on the distancetravelled or the number of hours of operation.The signal from the temperature sender beforeparticulate filter, the signal from the air mass meterand the signal from the exhaust gas pressure sensorform an inseparable unit during calculation of thelevel of carbon soot deposit in the particulate filter.This cycle for particulate filter regeneration, however,is not effective over a long period of time. After apredetermined number of cycles, the dieselparticulate filter warning lamp will light up and thenthe preglow control lamp will flash in the dash panelinsert. This informs the driver that the vehicle must bedriven to a workshop.Furthermore, the signal is used as a form ofcomponent protection to protect the particulate filteragainst high exhaust gas temperatures.22
Temperature sender before turbocharger G507S330 096S330 180The temperature sender before turbochargeris a PTC sensor. It can be found in the exhaust systembefore the turbocharger. There is measures thetemperature of the exhaust gas.Signal applicationEffects of signal failureThe engine control unit requires the signal from thetemperature sender before turbocharger to calculatestart of injection and the quantity of extendedinjection for regeneration. In this way, the requiredtemperature increase for combustion of the carbonsoot particles is reached.In addition, the signal is used to protect theturbocharger against excessively high temperaturesduring regeneration.In the event of failure from the temperature senderbefore turbocharger, the turbocharger can no longerbe protected against excessively high temperatures.Regeneration of the diesel particulate filter is stopped.By means of the preglow control lamp, the driver isinformed that the vehicle should be driven to aworkshop.To reduce the carbon soot emissions, exhaust gasrecirculation is switched off.23
Sensors and actuatorsLambda probe G39The lambda probe is of the broadband type. It can befound in the exhaust manifold before the oxidisingcatalytic converter.S330 098Signal applicationEffects of signal failureWith the lambda probe, the percentage of oxygen inthe exhaust gas can be determined across a widemeasuring range. In conjunction with the dieselparticulate filter system, the engine control unit usesthe signal from the lambda probe for precisecalculation of the quantity and start of extendedinjection for regeneration. For effective regenerationof the particulate filter, a minimal percentage ofoxygen in the exhaust gas is required at a continuallyhigh exhaust gas temperature. This regulation is madepossible by the signal from the lambda probe inconjunction with the signal from the temperaturesender before turbocharger.Regeneration of the particulate filter is not as efficientbut remains functional.In the event of lambda probe failure, there could bean increase in nitrogen oxide emissions.Detailed information about the broadband lambda probe can be found in self-study programme SSP231 "Euro onboard diagnosis for petrol engines".24
Air mass meter G70The hot film air mass meter is installed in the intakemanifold. Using the air mass meter, the engine controlunit can determine the actual mass of intake air.S330 184Signal applicationEffects of signal failureIn conjunction with the diesel particulate filter system,the signal is used for calculation of the exhaust gasvolume in order to determine the level of carbon sootdeposit in the particulate filter.In the event of signal failure from the air mass meter,the particulate filter regeneration cycle will be basedon the distance travelled or the number of hours ofoperation.The signal from the air mass meter, the signal from thetemperature sender before particulate filter and thesignal from the exhaust gas pressure sensor form aninseparable unit during calculation of the level ofcarbon soot deposit in the particulate filter.This cycle for particulate filter regeneration, however,is not effective over a long period of time. After apredetermined number of cycles, the diesel particulate filter warning lamp will light up and then thepreglow control lamp will flash in the dash panelinsert. This informs the driver that the vehicle must bedriven to a workshop.25
Sensors and actuatorsFuel additive tank sender G504The fuel additive tank sender can be found in theadditive tank.S330 146S330 138Signal applicationOnce the fill level in the additive tank reaches aminimum point, the preglow control lamp is activatedin the dash panel insert by the fuel additive tanksender signal. In this way, the driver is informed of amalfunction in the diesel particulate filter system andinstructed to seek a workshop.In the event of the additive quantity being too low,particulate filter regeneration is also stopped andengine performance is reduced.DesignPreglow control lampDash panel insertReed contactMagnetic ringFloat26S330 128
This is how it works:AdditiveFloatReed contactInstalled in the shaft of the fuel additive tank sender isa reed contact. It is activated by the magnetic ringinstalled on the float. If there is sufficient additive inthe tank, the float will be in contact with the upperstop. The reed contact is open.Magnetic ringS330 136AdditiveFloatReed contactIf there is not enough additive in the tank, the float willdrop to the lower stop. As it does this, the reed contactwill be closed by the magnetic ring. The preglowcontrol lamp lights up.Magnetic ringS330 134Effects of signal failureIn the event of signal failure from the additive tanksender, an entry is made in the fault memory of theengine control unit.27
Sensors and actuatorsThe actuatorsParticulate filter additive pump V135S330 150S330 148The particulate filter additive pump is of thereciprocating piston type, which delivers additive tothe fuel tank. It can be found bolted on the additivetank.Each time the fuel tank is replenished, the pump isactuated by the engine control unit in a cycle toensure the correct amount of additive is added.This is how it works:Additive deliveryInlet holeArmaturePump chamberTo fuel tankFrom additive tankBall valveCoilSpringWhen not energised, the pump is filled with additive.As soon as the engine control unit actuates theparticulate filter additive pump, the coil is energisedand the armature moves the pump plunger againstspring pressure. The pump plunger closes the inlethole to the pump chamber and forces the additive inthe chamber towards the ball valve.28Pump plungerS330 174This procedure results in a build up of pressure, whichcauses the ball valve and thereby the pump chamber toopen. The vol
The combustion quality depends on how well the fuel is mixed with the air. The mixture in some areas of the combustion chamber could be too rich because not enough oxygen is present. Combustion will then be incomplete and soot particles will be formed. Typical particle of soot caused from diesel engine combustion S330_013
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Exhaust leaks before or near the diesel particulate filter pressure sensor. Leaks in the diesel particulate filter pressure sensor connecting hose. Faulty diesel particulate filter. Defective pressure sensor. P244A - DPF differential pressure too low (Bank 1) P244B - DPF differential pressure too high (Bank 1)
Particulate matter: A mix of solid particles and liquid droplets found in the air, e.g., dust, soot or smoke. Fine particulate matter (PM 2.5) measures 2.5 micrometers and smaller. Coarse particulate matter (PM 10) measures 10 micrometers and smaller. Diesel particulate matter (DPM) is particulate matter that results from burning diesel fuel.
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