Detection of differential pressure sensor replacement

Abstract

To provide a method for detecting a replacement of a differential pressure sensor arranged for measuring a differential pressure across a filter of an aftertreatment system of a vehicle.SOLUTION: The method comprises: determining a sensor offset value being an offset from a sensor value measured with a differential pressure sensor; adding an adaption value to the measured sensor value to compensate for the offset value to centre the sensor value around a predetermined level; if a sum of a subsequently measured sensor value and the adaption value exceeds a limit value, concluding that the differential pressure sensor has been replaced. The invention also relates to an exhaust aftertreatment system, a vehicle comprising such a system, a computer program, a computer readable medium and a control unit configured to perform the steps of the method.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a method for detecting replacement of a differential pressure sensor arranged to measure the differential pressure across a filter of an aftertreatment system in a vehicle. The disclosure also relates to a corresponding exhaust aftertreatment system, a control unit, and a computer program. The method and system are described in relation to a vehicle in the form of a truck, but can also be effectively incorporated into other types of vehicles, such as buses and construction equipment. [Background technology]

[0002] All modern exhaust aftertreatment systems are equipped with a particulate filter that traps particles such as soot and ash produced by engine combustion.

[0003] To monitor the amount of soot and ash in the particulate filter, a pressure sensor is typically used to measure the differential pressure across the particulate filter. If the differential pressure rises above a certain threshold, a soot regeneration process for the filter is often initiated. The measured differential pressure is also used to perform on-board diagnostics (OBD) of the particulate filter.

[0004] Proper diagnosis of the pressure sensor is important to determine the current condition of the particulate filter. For example, if there is a certain offset in the signal from the pressure sensor, this offset must be handled by the control system. One way to handle a possible offset is to monitor the signal value when the engine is off and the vehicle is in the "key on" position. If the signal at that time is not zero, the sensor signal is compensated to be near zero.

[0005] However, if a large compensation value was recently added to the sensor signal to compensate for the offset, and then the sensor is replaced, all functions that rely on the compensated sensor signal must be reset. This reset is performed at the factory when the sensor is replaced. However, if this reset is not performed, there is a risk that the vehicle will misinterpret the signal value, including the added offset, as the actual value from the sensor. This could cause an OBD failure in one or more OBD monitors, such as the OBD monitor for the particulate filter and the OBD monitor for the pressure sensor itself. Therefore, a method that can detect when a pressure sensor has been replaced is useful. Summary of the Invention

[0006] It is an object of the present invention to provide a method for detecting replacement of a differential pressure sensor arranged to measure the differential pressure across a filter of an aftertreatment system in a vehicle, and at least partially alleviating the drawbacks of the prior art.

[0007] According to a first aspect of the present invention, this object is achieved by a method according to claim 1.

[0008] According to a first aspect of the present invention, there is provided a method for detecting replacement of a differential pressure sensor arranged to measure a differential pressure across a filter in an aftertreatment system in a vehicle, the method comprising: determining a sensor offset value, which is an offset of a sensor value measured by the differential pressure sensor; adding an adaptive value to the measured sensor value, the adaptive value being adapted to compensate for the offset value and bring the sensor value around a predetermined level; and determining that the differential pressure sensor has been replaced when the sum of a later measured sensor value and the adaptive value exceeds a limit value.

[0009] The present invention is based on the recognition that when a first differential pressure sensor is replaced with a new one without a software reset, such as at the factory, to reset the offset compensation, the adaptive value used for the first differential pressure sensor will cause the new differential pressure sensor to be offset from its intended center value at a predetermined level. That is, the adaptive value used to compensate for the sensor offset of the first differential pressure sensor will not adjust the sensor value to the predetermined level. Therefore, when the sum of the subsequently measured sensor value and the adaptive value significantly exceeds a limit value, either positively or negatively, it is determined that a new differential pressure sensor has been installed to replace the first differential pressure sensor.

[0010] The sign of the adaptation value is opposite to the sign of the sensor value offset. Thus, when the adaptation value is added to the sensor value, the compensated sensor value is at a predetermined level, preferably at or near zero. For example, when the sensor offset is positive relative to the predetermined level, the adaptation value is negative relative to the predetermined level, resulting in the sum of the positive sensor value and the negative adaptation value. When the sensor offset is negative relative to the predetermined level, the adaptation value is positive relative to the predetermined level, resulting in the sum of the negative sensor value and the positive adaptation value.

[0011] A new differential pressure sensor typically has no or very little offset from zero. Therefore, the predetermined level is preferably zero or close to zero. Thus, if the previous differential pressure sensor had a large offset that was compensated for by adding an adaptation value, when the previous differential pressure sensor is replaced with a new differential pressure sensor that has no or a small offset from zero, the sum of the new sensor value and the previous adaptation value will no longer be zero or close to zero. When this sum exceeds a limit value, which may be either a positive or negative value, sensor replacement is confirmed.

[0012] Therefore, by providing the method proposed herein, sensor value measurements can be used to determine sensor replacement and perform a software reset in a timely manner, thereby reducing the risk of having to return the vehicle to the factory and thereby reducing vehicle downtime, and further increasing the reliability of on-board functions that rely on accurate differential pressure sensor values.

[0013] The aftertreatment system is adapted to receive combustion gases from an engine, preferably an internal combustion engine, which may be a diesel engine, a gasoline engine, or any other type of internal combustion engine, and which may be part of a hybrid drivetrain that is partially battery-powered.

[0014] The limit value can be adapted to the particular type of vehicle and aftertreatment system. The fact that the sum of the subsequently measured sensor value and the adaptation value does not exceed the limit value typically indicates that the sum does not deviate more than an acceptable range from a predetermined level. Specifically, when the sum of the subsequently measured sensor value and the adaptation value does not exceed the limit value, the limit value should be adapted so that functions dependent on the sensor value can operate properly.

[0015] The limit value can be tailored to the particular application and its operating parameters. For example, the limit value may depend on the particular calibration of the soot and ash models and the diagnostic monitoring capabilities of the aftertreatment system. The limit value may also depend on the particular type of differential pressure sensor and its characteristics. The limit value may typically be a trade-off between excessive soot buildup in the filter and the risk of receiving frequent fault codes.

[0016] The filter may be a particulate filter in an aftertreatment system configured to trap particles such as soot and ash produced by engine combustion. In the case of a diesel engine, the filter is a diesel particulate filter (DPF).

[0017] According to an exemplary embodiment, the method can be executed only when predetermined vehicle conditions are met, thereby ensuring that the vehicle conditions are such that the sensor values ​​are not affected by factors that may cause a false detection of a sensor replacement. For example, the sensor values ​​should be measured under similar vehicle conditions so that the sensor value offset and the sum of the subsequently measured sensor value and the adaptation value can be determined sufficiently accurately.

[0018] The predetermined vehicle conditions may vary, but in some embodiments, include at least one of the following: the vehicle engine is off; the vehicle engine is idling; the filter temperature is within a predetermined range; and the ambient temperature is within a predetermined range. Having the engine off provides the advantageous condition of no mass flow in the aftertreatment system, which prevents the sensor value from being affected by changes in the pressure level across the filter. Preferably, the predetermined conditions are that the particulate filter is warm, e.g., warmer than the ambient temperature, and the differential pressure sensor is not exposed to water. That is, when the engine is off, the filter is relatively warm because the engine may have been running recently. The predetermined temperature range for the filter should be higher than a temperature that reliably prevents water from building up in the filter or on the pressure sensor, but preferably lower than the filter regeneration temperature. Preferably, the ambient temperature is above freezing so that the pressure sensor can provide accurate measurements.

[0019] According to an exemplary embodiment, the method may include, upon determining that the differential pressure sensor has been replaced, performing a reset of at least one software function that is affected by pressure values ​​measured by the differential pressure sensor. Such a reset may include resetting an adaptive value that adjusts subsequently measured sensor values ​​to a predetermined level. Advantageously, this reset may be performed automatically upon detection of a new differential pressure sensor, thereby reducing or even eliminating the risk that a software reset may be forgotten or otherwise not performed at the factory.

[0020] A reset can be thought of as returning a model or function to a pre-defined start-up state using its pre-defined parameters.

[0021] According to an exemplary embodiment, the at least one software function may include at least one of a sensor adaptation function configured to perform offset compensation of the vehicle's sensor values, a particulate filter soot or ash model, or an on-board diagnostic monitoring function. For example, historical data used by any of the functions or models may be reset to better match the new differential pressure sensor. The sensor adaptation function is configured to add an adaptation value to the sensor value provided by the differential pressure sensor.

[0022] According to an exemplary embodiment, the method may include, upon determining that the differential pressure sensor has been replaced, suspending operation of at least one of a particulate filter soot model or ash model and an on-board diagnostic monitoring function for the vehicle until a reset of the at least one software function is completed, thereby avoiding malfunction of functions that utilize the differential pressure sensor value.

[0023] According to an exemplary embodiment, the method may include, upon detecting that the sum of the subsequently detected sensor value and the adaptive value exceeds a limit value, providing a signal to a user interface indicating that a differential pressure sensor replacement has been detected and issuing a request for confirmation of the differential pressure sensor replacement. In other words, information indicating that a new sensor has been detected may be transmitted to a user interface, such as a factory computing device or a user's or technician's portable electronic device. In response, the user or technician may provide confirmation that the sensor has been replaced to the vehicle control unit via the user interface. In response to this confirmation, a software reset may be initiated automatically by the vehicle control unit or manually by the user or technician.

[0024] According to an exemplary embodiment, the method may include, upon receiving confirmation of the differential pressure sensor replacement, performing a reset of at least one software function affected by the pressure value measured by the differential pressure sensor, the software reset being initiated automatically by the vehicle control unit or manually by a user or technician in response to the confirmation.

[0025] According to an exemplary embodiment, the method may include storing the adaptation values ​​in memory, so that if new adaptation values ​​calculated after a software reset were determined based on erroneous input data, the previous adaptation values ​​can be applied.

[0026] Preferably, the predetermined level is at or near zero, which advantageously reflects the fact that most newer differential pressure sensors have an offset at or near zero.

[0027] According to a second aspect of the present invention, the above object is achieved by a system according to claim 11.

[0028] According to a second aspect of the present invention, there is provided an exhaust aftertreatment system for a vehicle, comprising: a particulate filter configured to trap particles in a combustion gas flow from a vehicle engine; a differential pressure sensor arranged to measure a pressure drop across the particulate filter; and a control unit configured to detect replacement of the differential pressure sensor by summing the measured sensor value with an adaptive value adapted to compensate for offset sensor values ​​to bring the measured sensor value around a predetermined level, wherein the control unit is configured to determine that the differential pressure sensor has been replaced when the sum exceeds a limit value.

[0029] The advantages and features of the second aspect of the present invention are generally similar to those described above with respect to the first aspect.

[0030] According to a third aspect of the present invention, there is provided a vehicle comprising an exhaust aftertreatment system according to the second aspect.

[0031] According to a fourth aspect of the present invention there is provided a computer program comprising program code means for carrying out the steps of the first aspect when the computer program is run on a computer.

[0032] According to a fifth aspect of the present invention there is provided a computer readable medium carrying a computer program product comprising program code means for performing the steps of the first aspect when the program product is run on a computer.

[0033] According to a sixth aspect of the present invention there is provided a control unit configured to detect replacement of a differential pressure sensor and to perform the steps of the method according to the first aspect.

[0034] The effects and features of the third, fourth, fifth and sixth aspects are generally similar to those described above with respect to the first aspect.

[0035] Further features and advantages will become apparent upon review of the appended claims and the following description. Those skilled in the art will appreciate that different features can be combined to create embodiments other than those described below without departing from the scope of the disclosure.

[0036] Embodiments of the invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0037] [Figure 1] 1 is a vehicle in the form of a truck according to an exemplary embodiment of the present invention; [Figure 2] 1 is a schematic diagram of an exhaust aftertreatment system according to an exemplary embodiment of the present invention; [Figure 3] 1 is a set of graphs conceptually illustrating a methodology according to an exemplary embodiment of the present invention. [Figure 4]3 is a flowchart of method steps according to an exemplary embodiment of the present invention. [Figure 5] 3 is a flowchart of method steps according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0038] The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. However, the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided for thoroughness and completeness. Those skilled in the art will recognize that many changes and modifications may be made within the scope of the appended claims. Like reference numerals refer to like elements throughout the description.

[0039] FIG. 1 shows a vehicle in the form of a truck 1 equipped with an engine 2, for example an internal combustion engine. The internal combustion engine may be, for example, a diesel engine, a hydrogen engine, a gasoline engine, or any other type of internal combustion engine. The truck 1 may also be a hybrid electric vehicle. The truck 1 further comprises an exhaust gas aftertreatment system 3, which may include, for example, a particulate filter, a catalytic converter, a urea injector, and a nitrogen oxide sensor. The specific configuration of the aftertreatment system 3 depends on the type of vehicle and its implementation details. The truck 1 further comprises a control unit 16, which will be described with reference to the subsequent figures.

[0040] 2 conceptually illustrates an exhaust aftertreatment system 3 according to an embodiment of the present invention. The exhaust aftertreatment system 3 comprises an exhaust pipe section 5 that routes exhaust gas 51 to an exhaust gas outlet 7. The exhaust pipe section 5 is part of a larger transport system for transporting exhaust gas from the engine 2 to the exhaust gas outlet 7. In general, the aftertreatment system 3 may include a catalytic unit (e.g., a selective catalytic reduction device), a urea injector, an ammonia slip catalyst, a diesel oxidation catalyst, a particulate filter, an exhaust gas temperature sensor, and other components known to those skilled in the art (not described in detail herein).

[0041] The exhaust aftertreatment system 3 includes a particulate filter 11 disposed in the exhaust pipe section 5 for capturing particles in the combustion gas 51 stream. Additionally, a differential pressure sensor 13 is disposed to measure the pressure drop across the particulate filter 11. The differential pressure sensor 13 is shown configured with one measurement point 14a upstream of the particulate filter 11 in the exhaust stream and one measurement point 14b downstream of the particulate filter 11. The differential pressure measurement can equally be performed using two separate absolute pressure measurement sensors, one disposed at a position 14a upstream of the filter 11 and the other disposed at a position 14b downstream of the filter 11. The difference between the sensor values ​​obtained by these two absolute pressure measurement sensors provides the differential pressure sensor value.

[0042] Also shown conceptually is a control unit 16 configured to receive sensor data from differential pressure sensor 13. Control unit 16 is further connected to a user interface 18 and a memory 20, which will be further described herein.

[0043] FIG. 3 conceptually illustrates a methodology according to an embodiment of the present invention, and FIG. 4 illustrates a flow chart of method steps according to an embodiment of the present invention.

[0044] Graph 302a in FIG. 3 shows the differential pressure sensor value as a function of time, and graph 302b shows the adaptive value as a function of time. Here, the sensor value and adaptive value are illustrated in units of volts or pascals. As described with reference to FIG. 2, the differential pressure sensor 13 is positioned to measure the pressure drop across the filter 11. The adaptive value is used to compensate for the sensor offset and adjust the sensor value to a predetermined level, preferably at or near zero. That is, the adaptive value shown in graph 302b is added to return the sensor value to a predetermined level, e.g., to zero the sensor value. This is reflected in graph 302c, which shows the compensated sensor offset. In other words, the compensated sensor offset shown in graph 302c is the sum of the adaptive value of graph 302b and the sensor value of graph 302a.

[0045] At time t1, the sensor value in graph 302a begins to drift to a higher value, i.e., a sensor offset appears. As a result, the adaptive value in graph 302b becomes more negative at the same rate so that the compensated sensor offset in graph 302c remains zero.

[0046] 4, in step S102, a sensor offset value is determined, which is the offset of the sensor value measured by the differential pressure sensor 13. An example of the sensor value is shown in graph 302a, and the deviation from zero is the sensor value offset.

[0047] In step S104, an adaptive value is added to the measured sensor value to compensate for the offset value and adjust the sensor value to near a predetermined level. That is, the sensor offset is compensated by adding the adaptive value to the measured sensor value. The adaptive value is conceptually shown in graph 302b of FIG. 3. Up until time t2, the sensor offset of the sensor value in graph 302a is properly compensated by the adaptive value. In other words, the compensated sensor offset value in graph 302c is adjusted to zero. The predetermined level described herein is preferably zero or close to zero.

[0048] Up until time t2, the sum of the measured sensor value and the adaptation value is relatively close to a predetermined level at or near zero, which is the level to which the measured sensor value should be matched by the adaptation value.

[0049] In step S106 of the flowchart in FIG. 4, if the sum of the subsequently measured sensor value and the adaptive value exceeds the limit value, it is determined that the differential pressure sensor 13 has been replaced.

[0050] At time t2, the sensor is replaced. As shown in graph 302a, the new sensor offset after time t2 is zero. This causes a sudden jump in the compensated sensor offset at time t2, as shown in graph 302c. Therefore, at or shortly after time t2, the sum of the subsequently measured sensor value and the adaptive value deviates from the sum before time t2 because the adaptive value is adapted to the sensor value measured before t1. After time t2, the sum of the measured sensor value and the adaptive value becomes negative and relatively large in absolute value. When this sum exceeds the limit value, it is determined that the differential pressure sensor has been replaced. In this case, the sum is negative, so the magnitude or absolute value of the sum can be compared to the limit value to determine whether the sensor has been replaced. Alternatively, when the sum is negative, it can be compared to the negative limit value. If the sum has a larger absolute value than the negative limit value, i.e., is more negative, it indicates a sensor replacement.

[0051] 2 is configured to receive sensor data from differential pressure sensor 13. Control unit 16 may continuously sum the received sensor value, which indicates the current differential pressure across filter 11, with an adaptive value adapted to compensate for sensor offset. When control unit 16 determines that the sum exceeds a limit value, the control unit determines that the differential pressure sensor has been replaced, i.e., generates a signal indicating differential pressure sensor replacement.

[0052] Preferably, the method proposed herein is executed only when predetermined conditions of the vehicle 1 are met, including at least one of the following: the vehicle engine 2 is stopped, the vehicle engine 2 is at idle, the filter temperature is within a predetermined range, and the ambient temperature is within a predetermined range. This ensures that conditions during subsequent measurements are repeatable and that different vehicle conditions between measurements do not affect the measured sensor offset.

[0053] Referring now to FIG. 5, the method may further include step S108, which includes performing a reset of at least one software function affected by the pressure value measured by the differential pressure sensor upon determining that the differential pressure sensor has been replaced. That is, the control unit 16 may reset one or more software functions operable on one or more vehicle electrical control units of the vehicle 1. This reset may include, for example, resetting or "zeroing" an adaptive value. Referring to graph 302b of FIG. 3, the adaptive value returns to zero immediately after time t2 when the sensor replacement is detected. Therefore, when the adaptive value is reset, the compensated sensor offset also returns to zero. This reflects the reset of the vehicle's adaptive value function, which is part of the function that compensates for the sensor value offset.

[0054] Other exemplary functions that may be reset by the control unit 16 include the vehicle's particulate filter soot or ash model or on-board diagnostic monitoring functions. A reset may involve deleting historical data for the model's function. For example, historical data used to build the particulate filter soot or ash model may be deleted to allow a new model to be built utilizing a new differential pressure sensor. In another example, diagnostic data related to the old sensor may also be deleted. A reset typically involves setting the parameters of a function or model to predefined initial values.

[0055] Furthermore, if it is determined in step S106 that the differential pressure sensor has been replaced, then in step S110, operation of at least one of the vehicle's particulate filter soot model function and on-board diagnostic monitoring function is suspended until the reset of the at least one software function is complete. The control unit 16 that executes the method for determining whether the sensor has been replaced may be configured to suspend functions that are affected by the measurement value of the differential pressure sensor 13 until the sensor replacement is complete.

[0056] Furthermore, if it is detected that the sum of the subsequently detected sensor value and the adaptive value exceeds the limit value, in step S112, a signal indicating that a differential pressure sensor replacement has been detected is provided to the user interface 18, and a request for confirmation of the differential pressure sensor replacement is issued. That is, the control unit 16 can provide a signal to the user interface 18 informing the user or technician that a new differential pressure sensor has been detected. At the same time, the control unit 16 is configured to provide a signal requesting that the user confirm that such a replacement has occurred. The user can provide this confirmation via the user interface 18. A signal indicating the confirmation of the sensor replacement is provided to the control unit 16 via the user interface 18. The user interface 18 can be, for example, a portable electronic device, a computer, a laptop, a tablet, etc. Various such interfaces are known per se and will not be described in detail herein.

[0057] Upon receiving confirmation of the differential pressure sensor replacement in step S112, a reset of at least one software function affected by the pressure value measured by the differential pressure sensor is performed in step S108. The confirmation is received by control unit 16, and control signals are sent by control unit 16 to reset each of the software functions.

[0058] Furthermore, in step S114, the control unit 16 may store the adaptation values ​​in memory 20, for example in non-transitory memory 20. In this way, if the new adaptation values ​​are based on erroneous data, the previous adaptation values ​​can be reused, allowing the adaptation function to revert to the previous adaptation values.

[0059] The control unit may include a microprocessor, a microcontroller, a programmable digital signal processor, or another programmable device. That is, the control unit includes electronic circuits and electronic connections (not shown) and a processing circuit (not shown) for communicating with different parts of the truck, such as the brakes, suspension, drivetrain, and in particular the electric engine, electric machinery, clutch, and gearbox, to at least partially operate the truck. The control unit may include modules that are hardware or software, or modules that are partly hardware and partly software, and may communicate using known transmission buses, such as a CAN bus and / or wireless communication capabilities. The processing circuit may be a general-purpose processor or a specific processor. The control unit includes a non-transitory memory for storing computer program code and data. Therefore, those skilled in the art will appreciate that the control unit may be embodied in many different configurations.

[0060] The control functions of the present disclosure can be implemented using existing computer processors, or by special purpose computer processors for appropriate systems incorporated for this or other purposes, or by hardwired systems. Embodiments within the scope of the present disclosure include program products including machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media may be any available medium accessible by a general-purpose or special-purpose computer or other machine with a processor. By way of example, such machine-readable media may include RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium usable to carry or store desired program code in the form of machine-executable instructions or data structures and accessible by a general-purpose or special-purpose computer or other machine with a processor. When information is transferred or provided to a machine over a network or another communications connection (hardwired, wireless, or a combination of hardwired or wireless), the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data that cause a general-purpose computer, special-purpose computer, or special-purpose processing machines to perform a certain function or group of functions.

[0061] While the figures show a certain sequence, the order of steps may differ from that shown. Also, two or more steps may be performed concurrently or with partial concurrence. Such variations depend on the software and hardware systems selected and the designer's preferences. All such variations are within the scope of this disclosure. Similarly, software implementations may be implemented using standard programming techniques using rule-based logic and other logic to perform the various connection, processing, comparison, and decision steps. Furthermore, while the present invention has been described with reference to specific exemplary embodiments thereof, many different alternatives, modifications, and the like will be apparent to those skilled in the art.

[0062] It should be understood that the present invention is not limited to the embodiments described above and shown in the drawings, but rather, those skilled in the art will recognize that many variations and modifications may be made within the scope of the appended claims.

Claims

1. A method for detecting replacement of a differential pressure sensor (13) arranged to measure a differential pressure at both ends of a filter (11) of a post-treatment system (3) in a vehicle (1), comprising: obtaining a sensor offset value which is an offset of a sensor value measured by the differential pressure sensor (13) (S102); adding an adaptation value adapted to compensate for the offset value and adjust the sensor value to near a predetermined level to the measured sensor value (S104); when the sum of a subsequently measured sensor value and the adaptation value exceeds a limit value, determining that the differential pressure sensor (13) has been replaced (S106); and a method including this.

2. The method according to claim 1, wherein the method is executed when a predetermined condition of the vehicle is satisfied.

3. The predetermined condition includes at least one of the vehicle engine being stopped, the vehicle engine being in an idle state, the temperature of the filter being within a predetermined range, and the ambient temperature being within a predetermined range. The method according to claim 2.

4. The method according to any one of claims 1 to 3, including performing a reset of at least one software function affected by a pressure value measured by the differential pressure sensor when it is determined that the differential pressure sensor has been replaced (S108).

5. The at least one software function includes at least one of a sensor adaptation function configured to perform offset compensation of sensor values of the vehicle, a soot model or an ash model of a particulate filter, or an on-vehicle diagnostic monitoring function. The method according to claim 4.

6. The method according to claim 4, including temporarily suspending the operation of at least one of a soot model or an ash model of the particulate filter of the vehicle and the on-vehicle diagnostic monitoring function until the reset of the at least one software function is completed when it is determined that the differential pressure sensor has been replaced (S110).

7. When it is detected that the sum of the subsequently detected sensor value and the adaptation value exceeds the limit value, providing a signal indicating that a differential pressure sensor replacement has been detected to a user interface (18) (S112); and issuing a confirmation request for the differential pressure sensor replacement. The method according to any one of claims 1 to 3.

8. The method according to claim 7, comprising performing a reset of at least one software function affected by a pressure value measured by the differential pressure sensor (S108) when receiving confirmation of the differential pressure sensor replacement.

9. The method according to any one of claims 1 to 3, comprising storing the adaptation value in a memory (20) (S114).

10. The method according to any one of claims 1 to 3, wherein the predetermined level is zero or close to zero.

11. An exhaust aftertreatment system (3) of a vehicle (1), a particulate filter (11) configured to capture particles in a combustion gas flow from a vehicle engine, a differential pressure sensor (13) configured to measure a pressure drop amount at both ends of the particulate filter, a control unit (16) configured to detect replacement of the differential pressure sensor by obtaining a sum of an adaptation value adapted to compensate an offset sensor value and a measured sensor value so as to adjust the measured sensor value to near a predetermined level comprising, wherein the control unit is configured to determine that the differential pressure sensor has been replaced when the sum exceeds a limit value. Exhaust aftertreatment system.

12. A vehicle (1) comprising the exhaust aftertreatment system according to claim 11.

13. A computer program comprising program code means for performing the method according to any one of claims 1 to 3 when executed on a computer.

14. A computer-readable medium carrying a computer program comprising program code means for performing the method according to any one of claims 1 to 3 when the program product is executed on a computer.

15. A control unit (16) for detecting replacement of a differential pressure sensor (13), a control unit configured to perform the method according to any one of claims 1 to 3.

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