GB2492356A

GB2492356A - Exhaust gas treatment system with fuel and urea injection

Info

Publication number: GB2492356A
Application number: GB1111004.6A
Authority: GB
Inventors: Antonio Arpaia; Massimiliano Melis
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2011-06-28
Filing date: 2011-06-28
Publication date: 2013-01-02
Also published as: GB201111004D0

Abstract

An exhaust gas treatment system for a diesel engine 110, the system comprising a selective catalytic reduction system (SCR) and diesel particulate filter (DPF) installed in the exhaust line 275 of the engine with one injector 10 installed in the exhaust line for injecting hydrocarbon (HC) and a urea catalyst, which are supplied by a first and a second pump respectively 11, 12, where the system further comprises at least one valve 15 for controlling the flow of the hydrocarbon and the urea catalyst into the injector. Preferably the valve is a two-way control valve with two operating positions, where the two pumps are connected to the inlet of the valve and the injector is connected to the outlet such that the first position of the pump delivers hydrocarbon and the second position delivers urea. A method of operating the system is also claimed.

Description

Exhaust gas treatment system with Urea and HC injection system and method for managing the same *.*.*

Technical field

The present invention relates to a system for treatment of exhaust gas produced by an engine, in particular the invention relates to an exhaust gas treatment system for a diesel engine, and a method for managing the same, with the injection of a fluid in the exhaust line of the engine in order to reduce the emissions.

Background

In the art are known exhaust gas treatment systems for the emissions reduction and in particular of particulates and oxides of nitrogen (NO) from the diesel engine exhaust gas. These systems are provided with aftertreatment devices installed along the exhaust line of the engine and typically comprise a diesel particulate filter (DPF) for control of particulates, and selective catalytic reduction (SCR) system for NO control.

It is kncwn in the art, to inject a reagent (catalyst) fluid in the exhaust line of the diesel engine in order to reduce emissions by means of the afore-mentioned aftertreatment devices. In particular, hydrocarbon based reagents, generally indicated as HC, like the same diesel fuel used for fuelling the engine, are injected in the exhaust line in order to promote the regeneration of diesel particulate filter (DPF) with the burning of soot accumulated therein. Furthermore, a fluid catalyst such as urea, or ammonia, or a combination thereof (generally in a water solution) are also injected into the exhaust line of the diesel engine in order to promote the reduction of nitrogen oxides (NO) in the selective cata]ytic reduction system (SOR) Hydrocarbon (HO) and the urea catalyst are injected into the exhaust gas produced by the engine by means of two separate injectors installed in the exhaust line.

Preferably the hydrocarbon injector (HO injector) is installed upstream of the diesel particulate filter (DPF) and the urea catalyst injector is installed upstream of the selective catalytic reduction system (5CR) Such a configuration, due to the number of components, and in particular the number of injectors needed for delivery hydrocarbon and urea in the exhaust line, leads to an high system complexity, high costs of production, and also to a reduced installation flexibility of the exhaust gas treatment system.

Therefore, there is a need of minimize problems of the known exhaust gas treatment systems, briefly discussed above, and in particular it is an object of an embodiment of the present invention to simplify the structure and configuration of known systems for the treatment of exhaust gas produced by an engine, allowing also a costs reduction.

Another object of an embodiment of the present invention is to provide an exhaust gas treatment system, and a method for managing the same, which can be produced, installed on the vehicle and used in a simple way, without reducing its exhaust gas treatment efficiency.

Summary

These and other objects are achieved by the exhaust gas treatment system according to claim 1, and the method for managing the sane according to claim 9. Further aspects of an embodiment of the present invention are set out in the dependent claims.

The present exhaust gas treatment system for a diesel engine comprises a selective catalytic reduction system (5CR) and a diesel particulate filter (DFF) installed in the exhaust line of the engine for receiving the exhaust gas flow therefrom. One injector is installed in the exhaust line for injecting in the exhaust gas flow hydrocarbon (HO) and a urea catalyst, which are respectively supplied by a first pump and a second pump.

The system further comprises at least one valve for controlling the flow of the hydrocarbon (HO) and the urea catalyst into the injector, respectively supplied by the first pump and second pump.

It has to be noted that the term "urea catalyst" is used herein to indicate urea, or ammonia, or a combination thereof, typically in water solutions, and also other known catalysts used in selective catalytic reduction system (5CR) for reducing nitrogen oxides NO in the exhaust gas (known as De-NO function) According to an aspect of an embodiment of the present invention the hydrocarbon (HO) injected into the exhaust line is the diesel fuel used to operate the engine.

Advantageously, by providing only one injector for delivery hydrocarbons and urea, the complexity of the treatment system can be reduced, also allowing improved packaging and higher installation flexibility thanks to the removal of one component form the exhaust line.

En particular, using only one injector for both hydrocarbon and urea leads to costs reduction around 20 Euros because of the removal of a dedicated injector installed in the exhaust line.

The injector is provided with at least one outlet opening for injecting the hydrocarbon (NC) into the exhaust line, and at least one outlet opening for injecting the urea catalyst into the exhaust line. As will be described later, by means of the control valve, HO and urea, can be injected into the exhaust line by means of the same injector, either separately or simultaneously.

According to an aspect of an embodiment of the present invention, the exhaust gas treatment comprises a two-way control valve movable into two operating positions, where HG and urea are respectively delivered from said pumps to the injector.

In another embodiment of the present invention a method for managing the exhaust gas treatment system is provided. The method comprises the step of generating a request signal of injection of hydrocarbon (1-IC) and/or urea catalyst in the exhaust line, and the step of operating the valve for delivering hydrocarbon (HC) and/or the urea catalyst to the injector, on the basis of the generated injection request signal, in order to control the injection of said hydrocarbon (HC) and said urea catalyst in the exhaust line.

Advantageously, the present method for managing the exhaust gas treatment system, allows to inject into the exhaust line hydrocarbon and urea catalyst by means of the same injector, either separately or simultaneously, on the basis of the generated injection request signal.

More in detail, the two-way control valve 15 of the exhaust gas treatment system can be moved in its first operating position A for delivering the hydrocarbon (HO) to the injector 10, or in said second position B for delivering the urea catalyst to the injector 10.

Moreover, when the regeneration of the OPF and the De-NOx functions are contemporary needed, the present exhaust gas treatment system, and the method for managing the same, allow to inject simultaneously hydrocarbon and urea, The method comprise the step of continuously operate the control valve, which is continuously moved between said first and second positions A and B for alternative delivering the hydrocarbon (HO) and the urea catalyst in the exhaust line by means of the same injector.

Another aspect of an embodiment of the invention provides a computer program comprising computer executable codes for carrying out the method for managing the exhaust gas treatment system of the engine, described above.

Brief Description of the Drawings

Other feature, advantages and details appear, by way of example only, in the following detailed description of embodiments, the detailed description referring to the drawings, in which: * Figures 1 and 2 show pcssible embodiments of an automotive system on which the * Figure 3 is a schematic block diagram showing a possible embodiment of the exhaust gas treatment system as disclosed herein; * Figure 4 is a schematic front view of the outlet openings of the injector used in an embodiment of the exhaust gas treatment system as disclosed herein;

Detailed Description

Figures 1 and 2 show an embodiment of an automotive system on which the exhaust gas treatment system disclosed herein can be installed, that includes an internal combustion engine (ICE) 110 having an engine block 120 defining at least one cylinder 125 having a piston 140 coupled to rotate a crankshaft 145. A cylinder head 130 cooperates with the piston 140 to define a combustion chamber 150. A fuel and air mixture (not shown) is disposed in the combustion chamber 150 and ignited, resulting in hot expanding exhaust gasses causing reciprocal movement of the piston 140. The fuel is provided by at least one fuel injector 160 and the air through at least one intake port 210. The fuel is provided at high pressure to the fuel injector 160 from a fuel rail 170 in fluid communication with a high pressure fuel pump 180 that increase the pressure of the fuel received from a fuel source 190, such as a fuel tank. Each of the cylinders 125 has at least two valves 215, actuated by a camshaft 135 rotating in time with the crankshaft 145. The valves 215 selectively allow air into the combustion chamber 150 from the port 210 and alternately allow exhaust gases to exit through a port 220.

In some examples, a cam phaser 155 may selectively vary the timing between the camshaft 135 and the crankshaft 145.

The air may be distributed to the air intake port(s) 210 through an intake manifold 200. An air intake duct 205 may provide air from the ambient environment to the intake manifold 200. In other embodiments, a throttle body 330 may be provided to regulate the flow of air into the manifold 200. In still other embodiments, a forced air system such as a turbocharger 230, having a compressor 240 rotationally coupled to a turbine 250, is provided. Rotation of the compressor 240 increases the pressure and temperature of the air in the duct 205 and manifold 200. An intercooler 260 disposed in the duct 205 may reduce the temperature of the air. The turbine 250 rotates by receiving exhaust gases from an exhaust manifold 225 that directs exhaust gases from the exhaust ports 220 and through a series of vanes prior to expansion through the turbine 250. The exhaust gases exit the turbine 250 and are directed into an exhaust system 270. This example shows a variable geometry turbine (VOT) with a VGT actuator 290 arranged to move the vanes to alter the flow of the exhaust gases through the turbine 250. In other embodiments, the turbocharger 230 may be fixed geometry and/or include a waste gate.

The exhaust system 270 may include an exhaust pipe, or exhaust line, 275 having one or more exhaust aftertreatment devices 280. The aftertreatment devices may be any device configured to change the composition of the exhaust gases.

Some examples of aftertreatment devices 280 include, but are not limited to, catalytic converters (two and three way) , oxidation catalysts, lean NOx traps, hydrocarbon adsorbers, selective catalytic reduction (3CR) systems, and particulate filters.

As already mentioned above, the present exhaust gas treatment system is installed on the exhaust line of the engine where are installed aftertreatment devices comprising at least a selective catalytic reduction (SCR) system and diesel particulate filter (OPF) Other embodiments may include an exhaust gas recirculation (EGR) system 300 coupled between the exhaust manifold 225 and the intake manifold 200. The EGR system 300 may include an EGR cooler 310 to reduce the temperature of the exhaust gases in the EGR system 300. An EGR valve 320 regulates a flow of exhaust gases in the EGR system 300.

The automotive system 100 may further include an electronic control unit (ECU) 450 in communication with one or more sensors and/or devices associated with the ICE 110. The ECU 450 may receive input signals from various sensors configured to generate the signals in proportion to various physical parameters associated with the ICE 110. The sensors include, but are not limited to, a mass airflow and temperature sensor 340, a manifold pressure and temperature sensor 350, a combustion pressure sensor 360, coolant and oil temperature and level sensors 380, a fuel rail pressure sensor 400, a cam position sensor 410, a crank position sensor 420, exhaust pressure and temperature sensors 430, an EGR temperature sensor 440, and an accelerator pedal position sensor 445. Furthermore, the ECU 450 may generate output signals to various control devices that are arranged to control the operation of the ICE 110, including, but not limited to, the fuel injectors 160, the throttle body 330, the EGR Valve 320, the VGT actuator 290, and the cam phaser 155. Note, dashed lines are used to indicate communication between the ECU 450 and the various sensors and devices, but some are omitted for clarity.

Turning now to the ECU 450, this apparatus may include a digital central processing unit (Cpu) in communication with a memory system and an interface bus. The cpu is configured to execute instructions stored as a program in the memory system, and send and receive signals to/from the interface bus. The memory system may include various storage types including optical storage, magnetic storage, solid state storage, and other non-volatile memory. The interface bus may be configured to send, receive, and modulate analog and/or digital signals to/from the various sensors and control devices. The program may embody the methods disclosed herein, allowing the Cpu to carryout out the steps of such methods and control the ICE 110.

Figure 3 is a schematic block diagram of an embodiment of the exhaust gas treatment system, installed on the exhaust line 275 of an internal combustion engine 110, along which are disposed aftertreatment devices, and in particular a selective catalytic reduction system (SCR) and a diesel particulate filter (DPE) . As will be described later in greater detail, an injector 10 of the exhaust gas treatment device is installed on the exhaust line 275 upstream of both the selective catalytic reduction system (SCR) and the diesel particulate filter (DPF) . Moreover, it has to be noted that, although in figure 3 the 3CR system is placed upstream of the DPF, the position of these aftertreatment devices could be inverted, i.e. by placing the OPF upstream of the 3CR system along the exhaust line 275, while maintaining the injector 10 upstream of both SCR and DPF.

As shown in Figure 3, the exhaust gas treatment system for a diesel engine 110, comprises a selective catalytic reduction system (3CR) and diesel particulate filter (OFF) installed in the exhaust line 275 of the engine 110 for receiving the exhaust gas flow therefrom.

One injector 10 is installed in the exhaust line 275, for injecting in the exhaust gas flow hydrocarbon (NC) and a urea catalyst, which are supplied by suitable means such as pumps (11 and 12) As already mentioned above, the term urea catalyst" is used herein to generally indicate urea, or ammonia, or a combination thereof (typically in water solution), and also other known catalysts used in selective catalytic reduction system (3CR) for NOx control.

According to an aspect of an embodiment of the present invention the hydrocarbon (HC) used to promote the regeneration of the diesel particulate filter COPE) is diesel fuel used to operate the engine 110.

The injector 10 is connected to a first pump 11 and a second pump 12, respectively used for providing the hydrocarbon (HC) and the urea catalyst to it, by means of a valve 15 intended to control the flow of the hydrocarbon (HC) and urea catalyst from each pump 11 and 12 into the injector 10.

Advantageously the presence of only one injector 10 for both hydrocarbon (HO) and urea catalyst leads to production and installation costs reductions, and also to an improved packaging and installation flexibility thanks to the removal of one component, i.e. one injector, placed on the exhaust line, with respect to the exhaust gas treatment systems known in the art.

The present exhaust gas treatment system further comprises tanks, or equivalent means (not illustrated in the figures), for storing the hydrocarbon (HO) and the urea catalyst. Preferably a first tank for storing the hydrocarbon (HO) is disposed in fluid connection with first pump 11, and a second tank for said urea catalyst is disposed in fluid connection with the second pump 12.

It has to be noted that, according to a further aspect of an embodiment of the present invention, the high pressure fuel pump 180 that increase the pressure of the fuel provided to the engine 110 can be used as a pump used for providing to the injector 10 the hydrocarbon (HO), and in particular the same fuel used for fuelling the engine. It is clear that in this configuration, the first tank for storing the hydrocarbon (HO) is the fuel source 190 where the fuel used for operating the engine 110 is stored.

Alternatively, the first pump 11 is an additional pump connected to the first tank (not shown in the figures) , or connected to said fuel source 190 where the fuel used for operating the engine 110 is stored.

The present exhaust gas treatment system further comprises at least one valve 15 for controlling the flow into the injector 10 of the hydrocarbon (HC) and the urea catalyst, which are respectively supplied by the first pump 11 and the second pump 12.

As shown in figure 3, the valve 15 is positioned between pumps (11 and 12) and the injector (10), and each pump is connected to an inlet portion of the valve, to supply the hydrocarbon and the urea catalyst to the injector 10, which is in turn connected to the outlet portion the valve 15.

According to a preferred aspect of an embodiment of the present invention, the valve 15 is a two-way control valve, which is movable in two operating positions, indicated in figure 3 with reference signs A and B. First and second pumps 11 and 12 are connected to the inlet portion of the two-way control valve 15 and the injector 10 is in turn connected to the outlet portion of the two-way control valve, thus it is possible to control of hydrocarbon and urea catalyst flow between pumps 11 and 12 and the injector 10.

In its first position A, the two-way control vale 15 delivers the hydrocarbon (HC) to said injector 10 supplied by the first pump 11, and in its second position B the valve 15 delivers the urea catalyst to the injector 10 supplied by the second pump 12.

The control vale 15 is operated, i.e. moved in its first cr second positions A and B in order to delivery hydrocarbon and urea catalyst to the injector 10, on the basis of a request signal of injection generated when the regeneration of the DPF and/or the reduction of the NO amount into the exhaust gas flow are needed.

In particular, when the regeneration of DPF is needed, and a request of hydrocarbon injection in generated, the valve 15 is moved into the first operating position A, in order to allow the hydrocarbon flow from the first pump 11 to the injector 10.

In the same way, when the De-N0 function is needed, and a request of urea injection in generated, the valve 15 is moved into the second operating position B, in order to allow the urea catalyst flow from the second pump 12 to the injector 10.

In some cases, it may be necessary to perform at the same time the regeneration of the DPF' and the De-NO function, thus there is the need of a simultaneous injection into the exhaust gas flow of hydrocarbon and urea. In these cases, the control valve 15 is operated to move continuously between the first and second positions A and B, for delivering in alternation the hydrocarbon (NC) and the urea catalyst in the exhaust line 275 by means of the same injector 10.

It has to be noted that, although in figure 3 is depicted an electrically operated valve 15, other known systems for operating the valve could be used allowing its positioning in said first and second positions A and B. Moreover, in a further embodiment, each pump 11 and 12 could be provided with a dedicated valve connected to the injector 10, each valve could be separately operated to control the hydrocarbon and urea catalyst flow to the injector 10.

As already mentioned above, the exhaust gas treatment system comprises only one injector 10 to which the hydrocarbon and the urea catalyst are delivered by means of a control valve 15 intended to control the flow supplied by pumps 11 and 12.

The injector 10 is provided with at least one outlet opening 10.1 for injecting the hydrocarbon (HO) into the exhaust line 275, and at least one outlet opening 10.2 for injecting the urea catalyst into the exhaust line 275.

Figure 4 shows a front view of the delivery portion of an embodiment of the injector 10, which is provided with four outlet openings 10.1 for injecting the hydrocarbon (HC) and four outlet openings 10.2 for injecting the urea catalyst.

Outlet openings 10.2 for injecting the urea catalyst are arranged into a circular inner area of the delivery front portion of the injector 10, and outlet openings 10.1 for injecting the hydrocarbon (HO) are arranged into an annular peripheral area.

Obviously, injector 10 could be provided with a different number of outlet openings 10.1 and 10.2 for injecting hydrocarbon and urea catalyst into the exhaust line 275, and also their arrangement on the delivery portion of the injector 10 could be changed, according to different possible layout.

The electronic control unit (ECU) 450 of the engine 110, is connected to the injector 10, to first and second pumps 11 and 12 and also to the valve 15.

In particular, ECU 450 operates the control valve 15 to control the hydrocarbon and urea flow from pumps 11 and 12 to the injector 10, and in the possible embodiment of the exhaust gas treatment system where the valve is a two-way control valve, the ECU operates it to move into the first operating position (A) to delivery the hydrocarbon (NC), and to the second operating position (B) to delivery urea catalyst to the injector 10. As already mentioned above, when it is necessary to perform at the same time the regeneration of the DPF and the De-NOx function, thus there is the need of a simultaneous injection into the exhaust gas flow of hydrocarbon and urea, the control valve 15 is operated by the ECU to move continuously between the first and second positions A and B, for alternative delivering the hydrocarbon (HO) and the urea catalyst in the exhaust line 275 by means of the same injector 10.

Will be now described the steps of the method for managing the exhaust gas treatment system described above.

The method comprises the step of generating a request signal of injection of hydrocarbon (f-IC) and/or urea catalyst in the exhaust line 275, and the step of operating the valve 15 for delivering hydrocarbon (1-IC) and/or the urea catalyst to the injector 10 in order to control the injection of said hydrocarbon (1-IC) and said urea catalyst in the exhaust line 275.

The request signal of injection is generated when the regeneration of the diesel particulate filter and the reduction of the amount of nitrogen oxides (NOx), the Dc-NOx function, are needed, either separately or simultaneously.

The conditions in which there is the need of injecting hydrocarbon (HO) and/or urea catalyst in the exhaust gas flow, are predetermined and stored, preferably in the ECU 450 of the engine 110, could depend on many factors, for example the DPF and SCR characteristics, the target emissions, the calibrated strategies of the regeneration of the DFF and of the reduction of the ND by the 3CR (De-NOx function), etc. It has to be noted that, the conditions in which there is the need of injecting hydrocarbon (HO) and/or urea catalyst in the exhaust gas flow, takes into account also the operating conditions of the engine 110, in order to evaluate if the engine operating point allows to perform the DPF regeneration and the De-NOx functions without negatively affecting the vehicle performance and customer feelings.

For example, by taking into account also the current operating conditions of the engine with by comparing current value with predetermined values, allows to carry out the regeneration of the diesel particulate filter, by the injection of the hydrocarbon (NC) into the exhaust line 275, without negatively affecting the engine performance and customer feelings, for example with undesired torque drop.

The present method for managing the treatment exhaust gas system, on the basis of the generation request signal allows to inject into the exhaust line 275 hydrocarbon and urea catalyst by means of the same injector 10, either separately or simultaneously.

More in detail, the two-way control valve 15 of the exhaust gas treatment system can be moved in its first operating position A for delivering the hydrocarbon (HC) to the injector 10, or in said second position B for delivering the urea catalyst to the injector 10.

Thus, when the injection of hydrocarbon in the exhaust gas flow is required, for example when there is the need to carry out the regeneration of the diesel particulate filter (DPF) , the valve 15 is moved in its first position A in order to allow the delivery of hydrocarbon by the first pump 11 to the injector 10. The hydrocarbon is injected into the exhaust line 275 by passing trough the outlet openings 10.1 of the injector 10 (see figure 4). In the same way, when the injection of urea in the exhaust gas flow is required, for example when there is the need to perform the reduction of nitrogen oxides in the exhaust gas flow, the valve 15 is moved in its second position B in order to allow the delivery of urea by the second pump 12 to the injector 10.

Moreover, the exhaust gas treatment system and the method for managing the same, allow to inject simultaneously hydrocarbon and urea, for example when the regeneration of the DPF and the De-NO functions are contemporary needed.

The method comprises the step of continuously operate the valve 15 which is continuously moved between said first and second positions A and B for alternative delivering the hydrocarbon (HC) and the urea catalyst in the exhaust line 275 by means of the same injector 10.

In particular, the valve is operated by the ECU with a frequency between the first and second positions A and B. The frequency of the injection of the urea and hydrocarbon is half of the operating frequency of the valve, i.e. the frequency of moving the valve between said first and second positions A and B. The method for managing an exhaust gas treatment system described above, may be carried out by means of a computer program comprising program codes (computer executable codes) for performing the method steps already described above.

The computer program comprises computer executable codes that can be stored on the ECU, or on a computer readable medium, or a storage unit, such as CD, DVD, flash memory, hard-disk, or the like. More in detail the engine control unit (ECU) comprises a digital central processing unit (CPU) and a storage memory for storing a computer program for carrying out the above disclosed method for managing the exhaust gas treatment system of the engine, the digital central processing unit (CPU) is able to receive and to execute said computer executable codes of the computer program.

The computer program comprises computer executable code for computer executable code for generating a request signal of injection of hydrocarbon (MC) and/or urea catalyst in the exhaust line 275 and a computer executable code for operating on the basis of the generated signal the control valve 15 for delivering the hydrocarbon (HO) and/or urea catalyst to injector 10 in order to control the injection of said hydrocarbon (HO) and said urea catalyst in the exhaust line 275.

While at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one b exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.

List of reference numerals 10; injector 10.1: hydrocarbon outlet opening 10.2: urea outlet opening 11: hydrocarbon pump 12: urea pump 15: valve DPF: diesel particulate filter SCR: selective catalytic reduction system 100: Automotive system 110: Internal Combustion Engine 120: Engine block 125: Cylinder 130: Cylinder head 135: Camshaft 140: Piston 145: Crankshaft 150: Combustion chamber 155: Cam phaser 160: Fuel injector 170: Fuel rail 180: High pressure fuel pump 190: Fuel source 200: Intake manifold 205: Air intake line 210: Intake port 215: Valves 220: Port 230: Turbocharger 240: Compressor 250: Turbine 260: Intercooler 270: Exhaust system 275: Exhaust line 280: After-treatment devices 290: Variable Geometry Turbine (VGT) actuator 300: Exhaust Gas Recirculation (EGR) system 310: EGR cooler 320: EGR valve 330: Throttle body 340: Mass airflow and temperature sensor 350: Manifold pressure and temperature sensor 360: combustion pressure sensor 380: coolant and oil temperature and level sensors 400: Fuel rail pressure sensor 410: cam position sensor 420: crank position sensor 430: Exhaust pressure and temperature sensor 440: EGR temperature sensor 445: Accelerator pedal position sensor 450: Electronic Control Unit (ECU)