With the diagnostic socket and diagnostic signals agreed, another standard was
.... 1996: The OBD-II specification is made mandatory for all cars sold in the .....
the company AUDI AG, in addition to Europe, was also prepared to the use of ...
Erasmus Intensive Programme Radom, 07-20.04.2013
Vehicle diagnostics European Onboard Diagnostic System msc eng. Przemysław Sander UTH Radom
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Plan of the Presentation 1. Introduction 2. What is EOBD/ OBD 3. Existing standard exhaust 4. History EOBD 5. EOBD Diagnostics
6. EURO 5/EURO 6 – Description
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Introduction The American Environmental Protection Agency and the European parliament have set targets for reducing the levels of pollution produced by passenger and commercial vehicles. In order to ensure that these targets can be met, manufacturers are required to build new vehicles which meet increasingly stiff emissions standards. The manufacturers must further maintain these emission standards for the useful life of the vehicle. In order to meet and maintain these standards the vehicles are fitted with On-Board Diagnostic systems which monitor the integrity and effectiveness of all emission related components. As vehicles are becoming more and more complex, many of the systems fitted to them are being controlled by electronic control modules. Most vehicles now have multiple control modules (e.g. Engine, Transmission, Body, Suspension, etc.) placed at different locations on the vehicle. The On-Board Diagnostic systems are integrated into the vehicle control modules. With so many different vehicle and component manufacturers, a common interface was required to communicate with these control modules. In 1988, the SAE (Society of Automotive Engineers) created a standard that defined a standard diagnostic socket (J1962) and a set of diagnostic test signals. With the diagnostic socket and diagnostic signals agreed, another standard was produced that defined a universal inspection and diagnosis method to ensure that a vehicle is performing to Original Equipment manufacturer (OEM) specifications. This standard is known as EOBD (European On-Board Diagnostics). The fundamental requirement for an EOBD system is that in the event of an emissions related component fault, a DTC (Diagnostic Trouble Code) will be stored in the memory of the control module responsible for that component, and a Malfunction Indicator Lamp (MIL) will illuminate on the vehicle's instrument pack to alert the driver. The DTC can then be retrieved using diagnostic equipment to determine the type and status of the fault.
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WHAT IS OBD/EOBD ?
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On-board diagnostics, or OBD, is an automotive term referring to a vehicle's self-diagnostic and reporting capability. OBD systems give the vehicle owner or a repair technician access to state of health information for various vehicle sub-systems. The amount of diagnostic information available via OBD has varied widely since the introduction in the early 1980s of on-board vehicle computers, which made OBD possible. Early instances of OBD would simply illuminate a malfunction indicator light, or MIL, if a problem was detected—but would not provide any information as to the nature of the problem. Modern OBD implementations use a standardized digital communications port to provide real-time data in addition to a standardized series of diagnostic trouble codes, or DTCs, which allow one to rapidly identify and remedy malfunctions within the vehicle.
EOBD - The EOBD (European On Board Diagnostics) regulations are the European equivalent of OBD-II, and apply to all passenger cars of category M1 (with no more than 8 passenger seats and a Gross Vehicle Weight rating of 2500 kg or less) first registered within EU member states since January 1, 2001 for petrol (gasoline) engined cars and since January 1, 2004 for diesel engined cars. For newly introduced models, the regulation dates applied a year earlier - January 1, 2000 for petrol and January 1, 2003 for diesel. For passenger cars with a Gross Vehicle Weight rating of greater than 2500 kg and for light commercial vehicles, the regulation dates applied from January 1, 2002 for petrol models, and January 1, 2007 for diesel models. The technical implementation of EOBD is essentially the same as OBD-II, with the same SAE J1962 diagnostic link connector and signal protocols being used. With Euro V and Euro VI emission standards, EOBD emission thresholds will be lower than previous Euro III and IV.
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exhaust emission limit values in the EURO standards for vehicles with petrol engine
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exhaust emission limit values in the EURO standards for vehicles with diesel engine
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Limiting the exhaust emissions of the individual components of exhaust from 1970 to 2005 in the U.S.
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LEV = Low Emission Vehicle ULEV = Ultra Low Emission Vehicle SULEV = Super Ultra Low Emission Vehicle BIN5 = Exhaust emission California and other states in the U.S. 10
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The potential for the reduction of CO2 emissions, depending on the type of engine
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Permissible limit value for diesel exhaust
EURO 3 - Since 2000, valid for new approved Car EURO3 exhaust emissions standard. It differs from its predecessor EURO2 tightening the roller dynamometer testing control and reduction of the limit values.
EURO 4 - standard in force since 2005 and replaces EROU3 standard. It means a further reduction allowable limits. Even today, more than 65 percent of all new Volkswagen approved engine diesel in Germany complies with the standard EU4 exhaust emissions.
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reduce emissions by reducing engine size and fuel consumption through new technologies while maintaining the same power
HISTORY OBD
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1969: Volkswagen introduces the first on-board computer system with scanning capability, in their fuel-injected Type 3 models. 1975: Datsun 280Z On-board computers begin appearing on consumer vehicles, largely motivated by their need for real-time tuning of fuel injection systems. Simple OBD implementations appear, though there is no standardization in what is monitored or how it is reported. 1980: General Motors implements a proprietary interface and protocol for testing of the Engine Control Module (ECM) on the vehicle assembly line. The 'assembly line diagnostic link' (ALDL) protocol communicates at 160 baud with Pulse-width modulation (PWM) signaling and monitors very few vehicle systems. Implemented on California vehicles for the 1980 model year, and the rest of the United States in 1981, the ALDL was not intended for use outside the factory. The only available function for the owner is "Blinky Codes". By connecting pins A and B (with ignition key ON and engine OFF), the 'Check Engine Light' (CEL) or 'Service Engine Soon' (SES) blinks out a two-digit number that corresponds to a specific error condition. Cadillac (gasoline) fuel-injected vehicles, however, are equipped with actual on-board diagnostics, providing trouble codes, actuator tests and sensor data through the new digital Electronic Climate Control display. Holding down 'Off' and 'Warmer' for several seconds activates the diagnostic mode without need for an external scan-tool. 1986: An upgraded version of the ALDL protocol appears which communicates at 8192 baud with half-duplex UART signaling. This protocol is defined in GM XDE-5024B. 1988: The Society of Automotive Engineers (SAE) recommends a standardized diagnostic connector and set of diagnostic test signals. 1991: The California Air Resources Board (CARB) requires that all new vehicles sold in California in 1991 and newer vehicles have some basic OBD capability. These requirements are generally referred to as "OBD-I", though this name is not applied until the introduction of OBD-II. The data link connector and its position are not standardized, nor is the data protocol.
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~1994: Motivated by a desire for a state-wide emissions testing program, the CARB issues the OBD-II specification and mandates that it be adopted for all cars sold in California starting in model year 1996 (see CCR Title 13 Section 1968.1 and 40 CFR Part 86 Section 86.094). The DTCs and connector suggested by the SAE are incorporated into this specification. 1996: The OBD-II specification is made mandatory for all cars sold in the United States.
2001: The European Union makes EOBD mandatory for all gasoline (petrol) vehicles sold in the European Union, starting in MY2001 (see European emission standards Directive 98/69/EC). 2004: The European Union makes EOBD mandatory for all diesel vehicles sold in the European Union 2008: All cars sold in the United States are required to use the ISO 15765-4 signaling standard (a variant of the Controller Area Network (CAN) bus).
2008: Certain light vehicles in China are required by the Environmental Protection Administration Office to implement OBD (standard GB18352) by July 1, 2008. Some regional exemptions may apply. 2010: HDOBD (heavy duty) specification is made mandatory for selected commercial (non-passenger car) engines sold in the United States.
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EOBD II
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Now an integral part of emission control and monitoring in the USA, the On-Board Diagnostics (OBD II) system will also be introduced within the European Union under the name Euro-On-Board Diagnostics (EOBD) from 1st January, 2000. Initially, the system will be available for petrol engines only, however, a version for diesel engines will follow in the foreseeable future.
There are very few differences between European variant of this diagnostic system and US OBD II. The only alterations made were those necessary to bring EOBD into line with European exhaust emission legislation. Other noteworthy features of EOBD are its central diagnosis interface and self-diagnosis fault warning lamp.
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LEGAL FRAMEWORK On 13th October 1998, the European Union passed the EU Directive 98/69/EC, according to which the introduction of EOBD is mandatory for all member countries. This directive has been adopted into national law in the Federal Republic of Germany. The introduction of EOBD is not directly coupled with an exhaust emission standard of the European Union (EU II, EU III, EU IV) or the Federal Republic of Germany (D2, D3, D4). Therefore, the target date for the introduction of OEBD and the associated transition period must be considered independently of the various exhaust emission standards. Target date for introduction of EOBD - With effect from the 1st January, 2000, the automobile industry will be required to perform only one type test for new petrolengined models if they have EOBD. Transition period - The transition period pertains to models which have been typetested prior to 31st December, 1999 and meet the EU II, D3 or D4 exhaust emission standard. The buyer may still register these vehicles until 31st December, 2000 and operate them without EOBD with no restrictions. With effect from this date, existing models will be required to have EOBD for initial registration purposes (buyer).
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OBDII System must have: - sold after 1 January 1996 in the u.s. - sold after 1 January 2001 the European Union - sold after 1 January 2002 in Poland - diesel cars sold after January 1, 2003 - cars sold earlier to have OBDII system,
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characteristic features of the EOBD -
standardised diagnostic plug connection; standardised error codes for all users; the ability to identify bugs through all available on the market diagnostic machines; the ability to determine the conditions of fault; normalizing the conditions regarding bugs indication emissions; standardisation of markings and parts on the shortcut and systems.
The basic features of OBD /OBD II - control of all devices having impact on the final emissions from vehicle; - the protection of catalytic reactor exhaust damage; - optical indications warning when the device shows fault functioning on the final emissions ; - the memory error.
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EOBD functions - The electrical functions of all components which are important for exhaust gas quality. - The functioning of all vehicle systems which have a bearing on exhaust gas quality (e.g. lambda probes, secondary air system, EGR,). - The functioning of the catalyst. - Misfiring. - CAN bus activity, - Proper operation of the automatic transmission.
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Characteristic elements of the EOBD
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Self-diagnosis fault warning lamp MIL (Malfunction Indicator Light)
If a fault impairing exhaust gas quality occurs on board the vehicle, the fault is saved to the fault memory and the self-diagnosis fault warning lamp is activated. If there is a risk of catalyst damage due to misfiring, the selfdiagnosis fault warning lamp flashes.
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Diagnosis interface
Stored EOBD data can be read out via the diagnosis interface. The fault codes are standardised so that data can be acquired using any Generic Scan Tool (OBD visual display unit). The diagnosis interface must be within easy reach of the driver's seat.
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The broadband lambda probe
(LSU . Lambda Probe Universal) is a new generation of lambda probes that are deployed before the catalyst. The name reveals the goals that were set for the development of this probe. The lambda value is represented by near-linear rises in current, and no longer by an abruptly rising voltage curve (which is the case with the step type lambda probe). As a result, it is possible to measure the lambda value over a larger measurement area (broader band). The conventional finger probes (LSH . Lambda Probe Heating) or Planar Lambda Probe (LSF . Lambda Probe Flat) are also known as step probes because of their step-like voltage curves. A step type lambda probe is used for the probe after the catalyst. The step-like measurement area of a step type lambda probe around the value lambda=1 (l=1) is sufficient for the probe after the catalyst to perform its monitoring function.
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Electrical exhaust gas recirculation system
The exhaust gas recirculation system is primarily used to increase fuel efficiency in low-displacement engines. As a result of the recirculating exhaust gases, the engine is required to induce less air. The resulting savings in suction work improve fuel efficiency.
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Electric throttle drive
The throttle valve was previously adjusted mechanically by means of a Bowden cable. The throttle valve was only actuated by electric motor when the engine was running at idling speed or when a cruise control system was in use. Use of the electrical throttle control enables the engine control unit to adapt the throttle valve position to the given basic conditions in any driving situation.
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Injection systems in modern diesel engines with direct injection
1 - Distribution of the high-pressure pump. - (Opel Ecotec 2,0 i 2,2 DI,) 2 - common rail – ( Renault, Daimler-Chrysler,Peugeot,) 3 -injectors (Volkswagen), 4 - system pump-injector-wire (np. Daimler-Chrysler i DAF.)
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Characteristic elements of the EOBD diesel cars, on the example of the motor system common rail
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the common rail system - scheme
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During combustion of diesel fuel, all sorts of different deposits are built up. Those that can be perceived directly as exhaust components on a cold engine are non or partly oxidised hydrocarbons in droplet form as white or blue smoke and strong smelling aldehyde. In addition to harmful gaseous substances, particles of solid substances are emitted with the emissions from diesel engines, which have been included under the main heading of particulates with regards to substances that are damaging to health and the environment.
in place of the catalyst system
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Harmful substances caused by combustion The harmful substances, and particulate emissions in particular, are influenced in a diesel engine by the combustion process. This process is affected by many factors relating to the construction, the fuel itself and the atmosphere. The following illustration shows an overview of the inlet and exhaust components of a diesel engine during combustion.
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The particulates Particulates is a term that covers all particles, solid or liquid, that are generated from friction, breakdown of components, erosion, condensation and incomplete combustion. These processes create particulates in different shapes, sizes and structures. Particulates have the same character as harmful substances in the air if, due to their small dimensions, they can float around in gaseous substances and damage organisms.
The carbon soot particles Carbon soot particles are generated from the combustion process in a diesel engine. Carbon soot particles are microscopic balls of carbon with a diameter of about 0.05 μm. Their core consists of pure carbon. Around the core are deposits of different hydrocarbon compounds, metal oxides and sulphur. Some hydrocarbon compounds are categorised as potentially hazardous to health. The exact composition of carbon soot particles depends on the engine technology, the conditions of use and the type of fuel.
SO4 (sulphate)
Hydrocarbons Carbon
Sulphur and metal oxides H2O (water)
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Internal engine measures A reduction in emissions can be achieved by measures to the internal workings of an engine.
Effective optimisation of the combustion process can ensure that harmful substances are not produced at all. Examples of internal engine measures are:
● the design of the inlet and exhaust ports for optimal flow properties,
● high injection pressures, for example from unit injector technology,
● the combustion chamber design, for example reduction in the size of the area where harmful substances are produced, design of the piston crown. 37
External engine measures The release of carbon soot particles that are produced during combustion can be prevented by external engine measures. This can be seen as the reduction of carbon 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 the catalytic coated diesel particulate filter. On the next few pages the design and function of just the catalytic coated diesel particulate filter will be described.
oxidation catalyst
Filter particulates and soot
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External engine measures
The release of carbon soot particles that are produced during combustion can be prevented by external engine measures. This can be seen as the reduction of carbon 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 the catalytic coated diesel particulate filter. On the next few pages the design and function of just the catalytic coated diesel particulate filter will be described.
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diagram of the exhaust system with particulate filter
1 Control unit in dash panel insert J285 2 Engine control unit 3 Air mass meter 4 Diesel engine 5 Temperature sender before turbocharger G507 6 Turbocharger 7 Temperature sender before particulate filter G506 8 Lambda probe G39 9 Particulate filter 10 Exhaust gas pressure sensor 1 G450 11 Temperature sender after particulate filter G527 12 Silencer
The overview shows a system with single exhaust pipe. On multi-pipe exhaust systems the particulate filter and the sensors on the exhaust system are installed for each set of cylinders.
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Exhaust gas recirculation (EGR) In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol/gasoline and diesel engines. EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders. In a gasoline engine, this inert exhaust displaces the amount of combustible matter because NOx forms primarily when a mixture of nitrogen and oxygen is subjected to high temperature, the lower combustion chamber temperatures caused by EGR reduces the amount of NOx the combustion generates. Most modern engines now require exhaust gas recirculation to meet emission standards.
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valves regulatory
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EGR system
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Exhaust gas pressure sensor Signal application Exhaust gas pressure sensor 1 measures the pressure difference in the flow of exhaust gas before and after the particulate filter. The signal from the exhaust gas pressure sensor, the signal from the temperature sender before and after particulate filter and the signal from the air mass meter form an inseparable unit during calculation of the level of carbon soot deposit in the particulate filter.
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Temperature sender before particulate filter
The temperature sender before particulate filter is a PTC sensor. On a sensor with PTC (positive temperature coefficient), resistance rises as temperature increases.
It can be found in the exhaust system before the diesel particulate filter. There it measures the temperature of the exhaust gas.
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Temperature sender after particulate filter
The temperature sender after particulate filter is a PTC sensor.
It can be found in the exhaust system after the diesel particulate filter. There it measures the temperature of the exhaust gas.
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Temperature sender before turbocharger
The temperature sender before turbocharger is a PTC sensor. It can be found in the exhaust system before the turbocharger. There is measures the temperature of the exhaust gas.
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The lambda probe
The lambda probe is of the broadband type. It can be found in the exhaust manifold before the oxidising catalytic converter.
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Air mass meter
The hot film air mass meter is installed in the intake manifold. Using the air mass meter, the engine control unit can determine the actual mass of intake air.
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The emissions When the regeneration cycle is active, there could be an increase in emissions. During regeneration, there is an oxidation process from carbon soot to carbon dioxide (CO2). If there is not enough oxygen available during this process, carbon monoxide (CO) will also be formed. By switching off the exhaust gas recirculation, the nitrogen oxide emissions increase slightly. To determine the emissions content, an emissions test is carried out (NEDC - New European Driving Cycle). During this test, the values from the cycle are evaluated with and without regeneration. With the average values, the vehicle must meet the EU4 emissions standard.
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Characteristic elements of the EOBD petrol cars
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fuel system diagram 2
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One of the main problems is gasoline direct injection exhaust treatment. The mixture of modes of stratified lean and homogeneous mix a large amount of nitrogen oxides, the three-way catalyst is not able to process. It was only thanks to the construction of tanks NOx catalysts engines meet the EU4 standard in these modes. Storage catalytic converter stores the nitrogen oxides, and then special procedure converts it to nitrogen. Another difficulty is that the presence of sulfur in gasoline. Its chemical similarity to nitrogen also makes it accumulate in the catalyst reservoir, occupying the space needed for the nitrogen oxides. The more sulfur in the fuel, the more need to carry out the recovery process of the catalyst, at a cost of an additional amount of fuel.
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exhaust
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Fuel supply system for variable capacity
Capacity control the fuel pump is a new option introduced in these engines. Since the pump pumps only as much fuel as high-pressure pump needs at any given time, reduced energy consumption, and thus the fuel.
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self-diagnosis and detection of the ignition system misfire as a catalyst protection A misfire - The system can instantly recognize a sensation, and block out quickly. The engine stumbles for a moment then regains its pace. Just as soon as the RPMs settle down, though, the misfire reappears, and you’re stuck with the sinking feeling that accompanies all automotive problems beyond the shadow of your wisdom: ―Something’s wrong‖
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EURO 5 i EURO 6
for example, the AUDI diesel engine
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Consistent continuation of the evolution of a TDI engine due to the need to develop the most "pure" motor diesel world. Therefore, the combustion process in the engine TDI has been consistently upgraded injection system fuel with a maximum injection pressure of 2000 bar ratio, greatly improved exhaust gas recirculation and the significantly upgraded turbocharger system are essential elements of this evolution. Integral mounted pressure control cylinders are also new. By means of such a package, in the first stage, emission from the engine is clearly reduced . In the second stage emission is reduced to the minimum level of nitrogen oxide by the use of an active exhaust aftertreatment system. Therefore, this issue of 'ultra-low' can, by appropriate combination of solutions within the motor in combination with a new type of exhaust aftertreatment systems, significantly minimalise emissions at the same time reduce fuel consumption. The aim of these projects was the consistent development of the TDI engine technology, designed to highlight the future EU6 emission limits as well as the most stringent limits II/BIN5 LEV standards so that the company AUDI AG, in addition to Europe, was also prepared to the use of these solutions in the world.
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In order to reduce emissions cars many vehicle manufacturers uses new design solutions
Exhaust gas recirculation (EGR)
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Episode exhaust gas recirculation system consists of microkatalizator, additional radiator and the EGR cooler, including a temperature sensor and an electric Liquid-cooled exhaust gas recirculation valve.
To achieve the low temperatures fed exhaust gas recirculation cooler is connected to a separate low-temperature coolant circuit (see page 13). Fluid Cooling is taken directly at the outlet of the main condenser and pumped by a pump power to the EGR cooler. Additional cooler is connected to the circuit engine cooling and allows to almost double their cooling capacity. Each of the two coolers, exhaust gas recirculation system is equipped with a bypass damper. This makes it possible, depending on demand, matching cooling capacity to the load point. In order to reduce emissions of carbon monoxide and hydrocarbons, valves during engine warm-up phase are set Bypass position.
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Adjusting the controlled combustion pressure in the cylinder A further component to maintain the lowest emissions at the same time shows the optimal consumption controlled combustion pressure cylinder. The pressure sensor used in the combustion chamber engine 3.0 l V6 TDI emissions system 'ultra-low' is development of Beru marked * PSG (Pressure Sensor Glow Plug). It extends the metal element glow of the function a pressure sensor in the combustion chamber and 2 mounted in the and 5 engine cylinder.
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During combustion controlled by pressure the cylinders are able to adapt injection time, and thus the pressure waveform ruling, during an incineration option for different fuel quality and the rate of change in the system exhaust gas recirculation. On the basis of the pressure signal from the pressure sensor in the combustion chamber and the speed signal engine combustion process is determined. Accordingly, the deviation resulting in comparison to the value required the actual value of the adjustment is determined to required combustion process, which interferes both the injection system as well as system air. Fuel quality, especially cetane number has a very large impact on the combustion process and the the velocity of the flame. In the case of low cetane number of the fuel's ability to ignition is significantly reduced, thereby greatly increases ignition delay. Central combustion point moves in the direction "late''. This leads to the occurrence of irregular ignitions or incomplete combustion..
In motors without control by pressure in the cylinders, the combustion process at very high doses of exhaust gas recirculation due very long delay and slowdown, may proceed incompletely. When it comes to the states Combustion similar to those found at irregular ignitions. By drastically increases HC and CO emissions. With the controlled combustion control by pressure in the combustion cylinders is maintained at a constant level and thus combustion is stabilised. Increased ignition delay prevents a shift to an earlier start injection. In this way the emission of HC and CO at low numbers cetane diesel, slight loads and higher speeds changes in the exhaust gas recirculation can be kept almost constant low level.
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diagram exhaust aftertreatment
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For this use is 32.5 percent aqueous solution of urea as the reducing agent (the reducing agent is distributed under the name of AdBlue ®), which is injected in small doses into the exhaust system.
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ADBLUE The reducing agent AdBlue ® As the reducing agent used is a transparent high purity 32.5 percent aqueous solution of urea, which is idespread in Europe under the name AdBlue ® in the U.S. referred to as Diesel Exhaust AdBlue ® fluid. The reducing agent is non-toxic, does not burn, biodegradable and is classified to the lowest substation class hazardous to water. Nor is it material or hazardous material. Properties of a reducing agent: - Freezes the temperature -11 ° C. - At high temperatures of around 70 ° C - 80 ° C, the reducing agent is decomposed and can have evolved because of the odor of ammonia. - Dated reducing agent greatly differs from the odor fresh solution, which has a neutral smell. - Refill expired reducing agent or a wrong recognized by NOx sensors in the exhaust system. - Diffuse reducing agent crystallizes to a white salt. - The reducing agent has a good ability to creep, because on the basis of capillary penetrates even the most narrow corners.
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Thank you for attention
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