Method and computer program product for adapting an air mass flow sensor of a motor vehicle motor arrangement

TECHNICAL FIELD

The present invention relates to a method for adapting an air mass flow sensor of a motor vehicle motor arrangement. The invention also relates to a computer program product comprising computer program code for implementing a method according to the invention. The invention further relates to a computer and a platform having a computer on-board, or to a platform allowing an external computer to be connected thereto.

BACKGROUND ART

Mass flow sensors are widely used in various applications. For example, air mass flow sensors are used for determining air intake flow in vehicles. It is of outmost importance to know a current air mass flow value in an air intake pipe of a vehicle. This value may be used for various calculations and modelling being executed by one ore more electronic control units of the vehicle. However, a mass flow sensor being provided in an air intake may generate air mass flow values which must be adjusted because of sensor inherent characteristics or vehicle unique conditions. Today there is performed an adaptation process of mass flow sensors being provided in for example heavy vehicles, such as trucks or buses, during drive of the vehicle. The air mass flow values generated by such an air mass flow sensor are adapted based upon a correction factor. This adaptation procedure is today performed more or less frequently during drive of the vehicle.

In case an air mass flow sensor is generating deviating air mass flow values the sensor may be malfunctioning. Alternatively, the sensor may generate deviating air mass flow values caused by of a vehicle state of condition

resulting in that the air mass flow sensor is measuring incorrect flow values. One such vehicle state of condition may be a leaking air intake pipe.

When there is generated air mass flow values which are deviating relative a predetermined model the electronic control unit may generate diagnostic trouble code (DTC). The DTC may not in every case provide information about the probable reason of the deviating air mass flow values, but merely indicate that an erroneous vehicle state of condition is provided. The generated DTC may be stored in a memory of an electronic control unit. The generated DTC may be read out by e.g. staff of a service central for providing information about what measurements should be taken.

The generated DTC may be of two different types. The first type is erasable, which means that the DTC e.g. may be manually invalidated if the error has been repaired. The second type is non-erasable, meaning that only a diagnosis system of the vehicle may invalidate the error code, in case the system determines that the error has been repaired. Such a diagnosis system is typically provided by an electronic control unit of the vehicle.

The diagnosis system of the vehicle may be arranged to invalidate generated DTC only when certain test conditions are fulfilled. One such condition may be where a predetermined air mass flow is detected by the air mass flow sensor. Another condition may be where a certain air mass flow has been detected during a predetermined time period.

Vehicles are regularly subjected to professional service at service centrals so as to e.g. detect erroneous components or components suffering from fatigue or wear. The staff at such a service centre has an interest in being sure that they have taken the correct measurements during a repair, of various reasons. It is today time consuming and labour-intensive for the service centre staff to take measurements to deal with vehicle errors being indicated by DTC-messages. Also, in particular, diagnostic trouble codes being

associated with the air mass flow sensor may be regulated by national law in such a way that the engine of the vehicle must be automatically controlled by the electronic control unit in a restrictive manner in case such codes are generated.

WO 2006/056355 A2 relates to a diagnostic and service system in a motor vehicle. There is provided a method for operating the diagnostic and service system in the motor vehicle, according to which actions and/or measurements are initiated in order to verify, diagnose and/or calibrate. The actions and/or measurements take place in an idle phase of the vehicle.

SUMMARY OF THE INVENTION

An object of the invention is to provide a new and advantageous manner of adapting an air flow sensor of a motor vehicle.

An object of the invention according to an aspect of the invention is to provide an improved method for adapting air mass flow sensor at a service centre, while the vehicle is standing substantially still.

Another object of the invention is to provide a more time efficient method for adapting an air mass flow sensor of a motor vehicle motor arrangement.

According to an aspect of the invention there is provided a method for adapting an air mass flow sensor of a motor vehicle motor arrangement, said method is characterized by the steps of:

- controlling air mass flow sensed by said air mass flow sensor for producing at least one air mass flow, which air mass flow is to be supplied to the motor;

- generating at least one adaptation value, based on an air mass flow value provided by said air mass flow sensor, for said at least one air mass flow, so as to allow adaptation of said air mass flow sensor.

The inventive method allows to generate adaptation values while the vehicle is standing still. By controlling the air mass flow which is to be supplied to the motor precise adaptation values may be generated in a user friendly manner. The method may advantageously provide a test procedure which allows to invalide DTC at the service centre without the time consuming necessity of driving the vehicle to be able to achieve various air mass flows.

Advantageously the engine speed may be controlled so as to achieve various, air mass flows. The engine speed of the engine may be controlled easily by e.g. an external computer at the test centre. By controlling the engine speed of the engine adaptation values may be generated for predetermined air mass flows, which provides a possibility to correct detected air mass flow values by use of the adaptation values.

Advantageously the VGT-unit may be controlled so also achieve various air mass flows. The VGT-unit may be controlled easily by e.g. an external computer at the test centre. By controlling the VGT-unit adaptation values may be generated for predetermined air mass flows, which provides a possibility to correct detected air mass flow values by use of the adaptation values.

As an effect of synergy very high air mass flows, e.g. air mass flows exceeding 20 kg/min may be achieved, even when the vehicle is standing still. Thus, by the inventive method adaptation values for more extreme air mass flows may be generated. Before, heavy loads and steep road slopes were necessary to generate adaptation values relevant for an air mass flow sensor calibration procedure.

According to one aspect of the invention the VGT-unit is controlled so as to achieve a desired air mass flow and wherein adjustment of this air mass flow may be achieved by controlling the engine speed of the engine, so as to be able to generate various adaptation values.

In an alternative embodiment of the invention the engine speed is controlled so as desired value and adjustment of this air mass flow is achieved by controlling the VGT-unit, so as to be able to generate various adaptation values.

Advantageously the method may comprise the step of controlling an EGR- unit of the motor arrangement. By eliminating the EGR-mass flow more precise adaptation values may be generated. By eliminating or minimizing, the EGR flow intake air mass flow is substantially equal to engine intake mass flow.

The produced at least one air mass flow may be a plurality of air mass flows and a plurality of adaptation values may be generated for each of the air mass flow values. This provides a better statistics for use in an adaptation process. For example, mean values of the generated adaptation values may be used for each of the air mass flow values, so as to allow calculation actual air mass flows based upon corrected/adjusted air mass flow values provided by the air mass flow sensor.

The step of controlling the air mass flow may be performed based upon whether a predetermined criterion is met or not. The criterion may pay regard to turbine speed of the VGT-unit and/or emission back pressure. By controlling the air mass flow only when the criterion is met, a more exact and accurate, adaptation of the air mass flow senior may be achieved.

In a case where DTC has been generated and the malfunctioning component has been repaired or replaced, but the DTC is of the type "non erasable", certain conditions must be fulfilled so that the adaptation may be performed. In a similar way, the inventive method according to the invention may establish that the malfunctioning component or erroneous vehicle state of condition is still provided in a case where an incorrect or incomplete repair work has been performed.

An advantage of the present invention is that the method for adapting an air flow sensor of a motor vehicle may be performed while the vehicle is standing still, e.g. in a service centre. The need of the staff driving the vehicle so as to perform the method of mass flow sensor adaptation for the purpose of invalidating error code is thus eliminated. If the staff would be compelled to drive the vehicle, it would perhaps have been necessary to connect a trailer to the vehicle to be able to achieve high mass flow values during performance of the inventive method. In practice this would have been an extra burden for the staff members of the service centre. Also, roads in the vicinity of the service centre may not always be ideal for providing required conditions. Now, in the light of the invention, the staff of the service centre will experience a more comfortable and effective test procedure so as to allow adaptation of the mass flow sensor and/or validation/invalidation of DTC. The inventive method thus provides a more user friendly way of performing the test procedure.

Because of the eliminated need of driving the vehicle during performance of the inventive method a very time efficient method is provided. It should also be noted that the method may be performed in a more environmental friendly manner because of the reduced required time, resulting in that less emissions are generated and outputted from the vehicle.

The method according to an aspect of the invention allows control of engine speed and control of the VGT of the vehicle, simultaneously, so as to control

air mass flow more precise. The method is robust and is applicable to various individual vehicles having different characteristics, such as engine type.

In a case where the air mass flow sensor has a torque reducing functionality an advantage of the present invention is also that the error may be taken care of at the service centre, so as to avoid delays during vehicle drive.

Advantageously stationary flows in both the inlet pipe and the emission pipe are achieved, which allows to perform the adaptation of the air mass flow sensor paying regard to a wide range of air mass flow values, e.g. 3-30 kg/minute.

A beneficial contribution of the invention is that a cost effective solution to the above stated problems is achieved. Existing electronic control units of the motor arrangement, external of the vehicle, or internal , being provided to implement the inventive method may easily be upgraded with relevant software so as to achieve the positive effects of the present invention.

Yet another beneficial contribution of the invention is that the method for adapting an air flow sensor of a motor vehicle motor arrangement is robust.

Additional objects, advantages and novel features of the present invention will become apparent to those skilled in the art from the following details, as well as by practice of the invention. While the invention is described below, it should be understood that the invention is not limited to the specific details disclosed. A person skilled in the art having access to the teachings herein will recognise additional applications, modifications and embodiments in other fields, which are within the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and further objects and advantages thereof, reference is now made to the examples shown in the accompanying drawings, in which:

Figure 1 schematically illustrates a platform according to an aspect of the present invention;

Figure 2a schematically illustrates a sub-system of a platform comprising a combustion engine and an electronic control unit therefore according to an aspect of the present invention;

Figure 2b schematically illustrates a combustion engine and an electronic control unit therefore according to an aspect of the present invention;

Figure 3a schematically illustrate a graph according to an aspect of the present invention;

Figure 3b schematically illustrates a graph according to an aspect of the present invention;

Figure 4 schematically illustrates a flow chart depicting a method for adapting an air flow sensor of a motor vehicle motor arrangement according to an aspect of the present invention;

Figure 5 schematically illustrates an electronic control unit according to an aspect of the invention.

DETAILED DESCRIPTION

With reference to Figure 1 , a platform in the form of a vehicle is shown. The platform is hereinafter referred to as vehicle 100. The vehicle 100 is preferably a heavy vehicle, such as a truck or lorry. It should be noted that the platform alternatively can be a water craft or underwater craft, e.g. a ship or submarine. Alternatively the platform can be a power plant. There is illustrated that the vehicle 100 has a first member 110 and a second member

112. The first member 110 is a conventional truck. The second member 112 is a trailer. The second member 112 is detachably connected to the first member 110. Alternatively the platform may be a private car.

Hereinafter the term "link" refers to a communication link which may be a physical connector, such as an optoelectronic communication wire, or a non- physical connector such as a wireless connection, for example a radio or microwave link.

With reference to Figure 2a, a part of a sub-system 20 of the platform 100 is shown. The sub-system 20 is depicted in greater detail with reference to Figure 2b, due to clarity issues. The sub-system 20 is a vehicle power system. The sub-system is also referred to as a motor vehicle motor arrangement. Fig. 2a shows a combustion engine 250 in the form of a schematically represented diesel engine having six cylinders. It should be noted that the invention is applicable to a vehicle having any multicylinder combustion engine with an arbitrary number of cylinders. The combustion engine 250 is also referred to as motor. The sub-system 20 is with advantage fitted to a heavy vehicle, such as truck, lorry or bus, for propelling the vehicle.

The engine 250 is arranged with an air-intake pipe 210 for supplying air from a surrounding of the vehicle to combustion chambers of the engine 250 in a known manner. The sub-system 20 is also arranged with an engine emission pipe 220 for outputting emissions from the engine 250 to a surrounding of the

vehicle in a known manner. The engine 250 is further arranged with a shaft 290 for transmission of power to wheels of the vehicle for propelling the same.

In a known fashion the sub-system 20 of the vehicle is provided with an exhaust gas recirculation pipe 230 being arranged between the engine emission pipe 220 and the air intake pipe 210 for providing emission gases from the emission pipe 220 to the air intake pipe 210. In this way at least a part of engine emission gases may be re-circulated within the sub-system 20.

Gas mass flows are herein denoted with the letter "W" and an index for further specifying a particular gas mass flow. Gas mass flows are given in the unit mass/time, such as kg/min. There are several gas mass flows indicated in the figure 2a. Gas mass flow indicating intake air gas flow is denoted Wair. Gas mass flow indicating gas flow which is inputted to the engine is denoted WenginelN. Gas mass flow indicating emission gas flow which is outputted from the engine is denoted WengineOUT. Gas mass flow indicating emission gas flow which is outputted from the emission pipe 220 is denoted Wem. Gas mass flow indicating exhaust gas being re-circulated within the exhaust gas recirculation pipe 230 is denoted WEGR.

The emission pipe 220 is provided with a VGT-unit (Variable Geometry Turbocharger unit) 286 being arranged to control the flow Wem from the engine 250 to the surrounding of the vehicle. The VGT-unit 286 is provided in a way known in the art. The VGT-unit 286 is co-operatively arranged with an air intake compressor 260 being arranged to compress intake air. An air mass flow sensor 281 is arranged to sense air mass flow Wair of intake air which has been compressed by the compressor 260. The VGT-unit 286 and the compressor 260 is physically connected to each other. The VGT-unit 286 is provided with a turbine which may be used to control rotational speed of the compressor 260. The VGT-unit 286 may thus be used to control the air mass flow Wair provided in the pipe 210.

The exhaust gas recirculation pipe 230 is provided with an EGR-unit (Exhaust Gas Recirculation unit) 287 being arranged to control the flow WEGR from the emission pipe 220 to the air intake pipe 210. EGR works by recirculating a portion of an exhaust gas of the engine back to the engine cylinders.

Basically, if the EGR-unit 287 is controlled so as to fully allow the WEGR flow within the pipe 230, the following theoretical relations may be established:

WenginelN=Wair+WEGR Wem=WengineOUT-WEGR

However, in a case where the EGR-unit 287 is controlled so as to totally interrupt the WEGR flow within the pipe 230, the following theoretical relations may be established:

Wair=WenginelN Wengine OUT=Wem

With reference to Figure 2b, the sub-system 20 of the platform 100 as depicted with reference to Figure 2a is illustrated in greater detail.

The sub-system 20 is provided with an air mass flow sensor 281 being provided in the air-intake pipe 210. The air mass flow sensor 281 is arranged to detect an inlet flow of air. The compressor 260 is arranged to compress inlet air. Detection may be performed continuously, or stochastically, or in any suitable manner, e.g. every second or minute. The air mass flow sensor

281 may be any suitable mass flow sensor known in the art. The air mass flow sensor 281 is arranged for communication with an electronic control unit

200 via a link 271. The air mass flow sensor 281 is arranged to detected air

mass flow values Wair* and to send air mass flow signals SWair comprising said air mass flow values Wair ^* to the ECU 200. An air mass flow signal SWair may comprise one or more sensed air mass flow values Wair ^* .

The sensed air mass flow values SWair may differ from the actual air mass flow provided in the pipe 210. This difference may be compensated for according to the invention.

A first pressure sensor 282 is arranged upstream the engine so as to measure a first pressure P1 in the air intake pipe 210. The first pressure sensor 272 is arranged for communication with the ECU 200 via a link 272. The first pressure sensor 282 is arranged to send a first pressure signal SP1 to the ECU 200. The first pressure signal SP1 comprises information about measured pressure upstream the engine 250.

A temperature sensor 283 is arranged upstream the engine so as to measure a temperature T of the gas in the air intake pipe 210, in a close proximity of the engine 250. The temperature sensor 283 is arranged for communication with the ECU 200 via a link 273. The temperature sensor 283 is arranged to send a temperature signal ST to the ECU 200. The temperature signal ST comprises information about measured temperature of the gas upstream the engine 250.

A second pressure sensor 285 is arranged down-stream the engine so as to measure a second pressure P2 in the engine emission pipe 220, in a close proximity of the engine 250. The second pressure sensor 285 is arranged for communication with the ECU 200 via a link 275. The second pressure sensor

285 is arranged to send a second pressure signal SP2 to the ECU 200. The second pressure signal SP2 comprises information about measured pressure downstream the engine 250.

The electronic control unit 200 is arranged to receive sensed engine data in the form of e.g. a toothed fly wheel signal (TF-signal). The TF-signal is received on a data communications port from an engine-speed sensor unit 284 which senses rotation of the engine's toothed fly wheel (not shown). The engine-speed sensor 284 may be e.g. an inductive type sensor or a Hall- effect sensor. Of course there may be more than one engine-speed sensor unit and other positions for measuring engine speed, such as measuring the camshaft speed of the engine 250, or an alternator speed. The engine speed sensor unit 284 is arranged for communication with the ECU 200 via a link 274.

The VGT-unit 286 is provided at the engine emission pipe 220 in any known fashion. The ECU 200 is arranged for communication with the VGT-unit 286 via a link 276. The ECU 200 is arranged to control the VGT-unit 286 via the link 276 by means of a VGT control signal SVGT. The VGT-unit 286 is arranged to detect internal turbine speed, and to send a turbine speed signal STS to the ECU 200.

The EGR unit 287 is provided in the exhaust gas recirculation pipe 230 in a known fashion. The ECU 200 is arranged for communication with the EGR- unit 287 via a link 277. The ECU 200 is arranged to control the EGR-unit 287 via the link 277 by means of an EGR control signal SEGR.

A fuel injection device 288 is arranged to provide fuel to the combustion chambers of the engine 250. A fuel mass flow of the fuel injection device 288 is denoted Wfuel. The ECU 200 is arranged for communication with the fuel injection device 288 via a link 278. The ECU 200 is arranged to control the fuel injection device 288 via the link 278 by means of a fuel injection control signal SINJ.

Herein, the inventive method is initiated and controlled by means of the electronic control unit. Alternatively, the inventive method is initiated and

controlled by means of an external PC 205. The external computer 205 may be directly connected to the electronic control unit 200 via a link 279, but may also be indirectly connected to the electronic control unit in any suitable manner, such as through an internal vehicle internal network. The communication between the external computer 205 and the engine control unit 200 may be partly or entirely wireless. The inventive method could also be initiated and controlled by the electronic control unit 200, itself or by another electronic control unit, such as an electronic gear box control unit connected to the fuel injection system via a vehicle internal network.

According to one embodiment of the invention the inventive method is initiated by service staff of a vehicle service centre by means of the external computer 205.

The gas mass flow WenginelN is calculated according to a predetermined model.

Figure 3a is an example graph wherein adaptation values k are plotted as a function of air mass flow W. According to this example software routines being stored in the ECU 200 are arranged to generate adaptation values, each corresponding to a predetermined air mass flow value, e.g. the ones indicated in Figure 3a. According to this example each adaptation value in the graph is a mean value of an arbitrary number of adaptation values each mean value is corresponding to a particular predetermined air mass flow value.

The adaptation values are calculated according to the formula

WenginelN - Wair *

^■ = k

Wair '

Where Wair ^* is a detected air mass flow value corresponding to an air mass flow provided in the pipe 210. WenginelN is calculated according to a predetermined model known in the art, for example, information carried by the signals SP1 , ST, SP2 and TF.

For example, a predetermined air mass flow value of 3 kg/min, which may correspond to a situation where the engine of the vehicle is running on idle speed, a mean value of a serial sequence of generated correction coefficient value currently corresponds to a correction coefficient value of about 5%.

It is also shown that a predetermined air mass flow value of 30 kg/min, which corresponds to a situation where the engine of the vehicle is subjected to a maximum load and is running on high engine speed, a mean value of generated adaptation values k is about 6%. It should be noted that adaptation values may have a negative sign.

The adaptation values correspond to the predetermined mass flow values may be continuously updated based on detected air mass flow Wair ^* during vehicle drive.

It is shown in Figure 3a that an adaptation value corresponding to the air mass flow value of 18 kg/min is substantially higher than the adaptation values corresponding to the other mass flow values. The adaptation value corresponding to the mass flow value of 18 kg/min is about 33%. According to this example a predetermined threshold value of the adaptation values is 30%. This means that if one or more adaptation values is determined to be above the predetermined threshold value of 30%, there is generated a TDC message indicating that there is a probable error within the sub-system 20, such as a faulty air mass flow sensor or a leakage in e.g. the pipe 210. The error message may be displayed for a driver of the vehicle and/or being stored in the ECU 200.

In case a TDC message is generated the adaptation values currently being stored in a memory of the ECU 200 may be set to zero (0). In such a situation new adaptation values should be generated, at that is made possible by the inventive method according to the invention.

It should be noted that adaptation values k may be generated for an arbitrary number of air mass flow values. Each adaptation value may be generated on the basis of a detected air mass flow value Wair*. Generation of adaptation values may be performed in any suitable order. For example, one or more adaptation values k may be generated in a sequential manner starting from a lowest air mass flow value sequentially increasing to a highest air mass flow value. According to one example, one adaptation value k is generated for each predetermined air mass flow value, while controlling the air mass flow in the air intake pipe such that generation of adaptation values starts with a lowest air mass flow value and is running forth and back between the lowest air mass flow value and a highest air mass flow value. Generation of adaptation values may start or end at an arbitrary air mass flow value. Of course any suitable polynomial may be used to depict adaptation values corresponding to an interval of air mass flow values.

Figure 3b schematically illustrates different VGT-states corresponding to different vehicle test modes.

A first test mode #1 is corresponding to a VGT-state A. The first test mode #1 is a mode where no test is performed. Herein a test means a procedure where e.g. service staff of a service centre has connected an external computer to the ECU 200 of the vehicle so as to perform the method of adapting the air mass flow sensor of the motor vehicle motor arrangement.

The VGT-state A is a state where the VGT-unit of the vehicle is substantially open, meaning that the turbine of the VGT is running on low speed.

A second test mode #2 is corresponding to a VGT-state B wherein a turbine speed, which is substantially higher than in the first vehicle mode is provided.

It should be noted that the inventive method according to the second mode #2 is performed having a substantially constant turbine position of the VGT- unit. To be able to generate adaptation values for different air mass flows, the engine speed of the motor vehicle motor arrangement should be varied.

A third test mode #3 is corresponding to a VGT-state C where a variable turbine position which is substantially higher than in the second vehicle mode, is provided. Alternatively, VGT= state C may be lower than in the second vehicle mode. According to this example adaptation values are generated when having fix engine speed while the turbine position is varied over time, which is schematically illustrated with reference to the VGT-state C.

Of course, according to another example, both the engine speed and the VGT-unit may be controlled simultaneously so as to achieve a desired air mass flow

Figure 4 schematically illustrates a method for adapting an air mass flow sensor of a motor vehicle motor arrangement. According to one aspect a number of predetermined criterions should be met before the adaptation of the mass flow sensor is performed.

The method comprises a first method step s410. The method step s410 comprises the step of controlling the EGR-unit 287 being provided at the pipe 230 of the sub-system 20 of the vehicle 100. By controlling the EGR-unit 287 in such a way that the mass flow is minimised or substantially throttled down, meaning that there is substantially no flow through the EGR-unit 287 the inventive method may be performed. By controlling the EGR-unit 287 the air mass flow Wair is substantially the same as WenginelN. The advantages

thereof are mentioned above. After the method step s410 a subsequent method step s415 is performed.

The method step s415 comprises the step of controlling the engine speed of the engine so as to provide a desired air mass flow Wair in the pipe 210. After the method step s415 a subsequent method step s420 is performed.

The method step s420 comprises the step of determining whether a predetermined test criterion is met. The criterion is a predetermined criterion. The criterion may be arbitrarily set. The criterion may pay regard to parameters such as exhaust manifold pressure P2, turbine speed N and/or engine speed. The test criterion may also pay regard to transients of various kinds, engine temperature or other. If the criterion is met a subsequent method step s430 is performed. If the criterion is not met a subsequent method step s425 is performed.

The method step s425 comprises the step of controlling the VGT-unit 286 being provided at the pipe 220 of the sub-system 20 of the vehicle 100. By controlling the VGT-unit 286 the air mass flow Wair may be controlled. In particular, by controlling the VGT-unit 286, a high air mass flow Wair may be achieved, e.g. 30 kg/min or more. This is a main advantage of the invention. Thereby it is possible to perform adaptation of mass flow sensors, when the vehicle is standing still. After the method step s425 a subsequent method step s427 is performed.

In the method step s427 it is determined whether the test criterion is met. The step s427 is substantially identical with the method step s420. If the criterion is met a subsequent method step s430 is performed. If the criterion is not met the method step s415 is performed.

The method step s430 comprises the step of generating an adaptation value k corresponding to the desired mass flow value as achieved in method step s425.

The method step s430 comprises the step of storing the generated adaptation value k.

After the method step s430 a subsequent method step s435 is performed.

The method step s435 comprises the step of determining whether adaptation values for all desired air mass flows have been generated. It not, the method step s415 is performed, and in this way a predetermined number of iterations are performed until all desired adaptation values have been generated, each adaptation value corresponding to one air mass flow value. If yes, the method ends.

With reference to Figure 5, a diagram of one embodiment of the electronic control unit 200 is shown. The electronic control unit 200 is also referred to as apparatus. The apparatus 200 comprises a non-volatile memory 520, a data processing device 510 and a read/write memory 550. Non-volatile memory 520 has a first memory portion 530 wherein a computer program, such as an operating system, is stored for controlling the function of the apparatus. Further, the apparatus comprises a bus controller, a serial communication port, l/O-means, an A/D-converter, a time date entry and transmission unit, an event counter and an interrupt controller (not shown). Non-volatile memory 520 also has a second memory portion 540.

A computer program P comprising routines for adapting an air mass flow sensor of a motor vehicle motor arrangement may be stored in an executable manner or in a compressed state in a separate memory 560 and/or in read/write memory 550. The memory 560 is a non-volatile memory, such as

a flash memory, an EPROM, an EEPROM or a ROM. The memory 560 is a computer program product. The memory 550 is a computer program product.

When it is stated that the data processing device 510 performs a certain function it should be understood that the data processing device 510 performs a certain part of the program which is stored in the separate memory 560, or a certain part of the program which is stored in the read/write memory 550.

The data processing device 510 may communicate with a data communications port 599 by means of a data bus 515. The non-volatile memory 520 is adapted for communication with the data processing device 510 via a data bus 512. The separate memory 560 is adapted for communication with the data processing device 510 via a data bus 511. The read/write memory 550 is adapted for communication with the data processing device 510 via a data bus 514.

When data is received on the data port 599 from the air mass flow sensor unit 271 it is temporarily stored in the second memory portion 540. When the received input data has been temporarily stored, the data processing device 510 is set up to perform execution of code in a manner described above. According to an embodiment of the invention, data received on the data port 599 comprises information about detected air mass flow. The processing device is arranged to generate adaptation values based on at least one air mass flow value.

Parts of the methods described herein can be performed by the apparatus by means of the data processing device 510 running the program stored in the separate memory 560 or the read/write memory 550. When the apparatus runs the program, parts of the methods described herein are executed.

According to an aspect of the invention the apparatus is arranged to run a computer program for adapting an air flow sensor of a motor vehicle motor arrangement comprising computer readable program code means for causing an the apparatus, an electronic control unit or another computer connected to the electronic control unit to perform the steps of:

- controlling air mass flow sensed by said air mass flow sensor for producing at least one air mass flow, which air mass flow is to be supplied to the motor;

- generating at least one adaptation value, based on an air mass flow value provided by said air mass flow sensor, for said at least one air mass flow, so as to allow adaptation of said air mass flow sensor.

The invention also relates to a computer program for adapting an air mass flow sensor of a motor vehicle motor arrangement, comprising computer readable program code means for causing an electronic control unit or another computer connected to the electronic control unit to perform the steps of:

- controlling air mass flow sensed by said air mass flow sensor for producing at least one air mass flow, which air mass flow is to be supplied to the motor; - generating at least one adaptation value, based on an air mass flow value provided by said air mass flow sensor, for said at least one air mass flow, so as to allow adaptation of said air mass flow sensor.

According to an embodiment the computer program comprises computer readable means for causing the electronic control unit or another computer connected to the electronic control unit to perform the step of:

- controlling a VGT-unit of the motor arrangement.

According to an embodiment the computer program comprises computer readable means for causing the electronic control unit or another computer connected to the electronic control unit to perform the step of controlling air mass flow, which step comprises the step of:

- controlling engine speed of an engine of the motor arrangement.

According to an embodiment of the computer program the step of controlling the VGT-unit is based upon the step of controlling engine speed, or the step of controlling the engine speed is based upon the step of controlling the VGT- unit.

According to an embodiment the computer program comprises computer readable means for causing the electronic control unit or another computer connected to the electronic control unit to perform the step of controlling air mass flow, which step comprises the step of:

-controlling an EGR-unit of the motor arrangement so as to substantially minimize a mass flow through the EGR-unit.

According to an embodiment of the computer program said produced at least one air mass flow is a plurality of air mass flows and in that a plurality of adaptation values are generated for each of said provided air mass flow values.

According to an embodiment of the computer program the step of controlling the air mass flow is performed based upon whether a predetermined criterion is met or not.

The invention also relates to a computer program product comprising a computer program and a computer readable medium on which the computer program is stored.

The invention also relates to a computer, such as an embedded electronic control unit or a vehicle external computer comprising a storing means and a computer program stored in the storing means.

The invention also relates to a platform comprising a computer according to above.

According to an embodiment the platform platform is chosen among a group comprising vehicle, water craft and under water craft, such as truck, ship and submarine, respectively, or a power plant.

The foregoing description of the preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated.