Method and device for monitoring the low-pressure sensor of the fuel system of an internal combustion engine

Abstract

Device (101) for checking a low-pressure sensor (107) of a low-pressure system of a fuel system (100) for supplying fuel (103) to an internal combustion engine (110); wherein the device (101) is configured, - to recognize, based on a measurement signal (202) from the low-pressure sensor (107), that a first criterion for the presence of an impairment of the low-pressure sensor (107) is fulfilled; and - in response to the recognition that the first criterion is met, to check whether the low pressure sensor (107) is impaired by means of a change in a target pressure (201) of fuel (103) in the low pressure system.

Description

[0001] The invention relates to a method and a corresponding device designed to monitor the low-pressure sensor of the low-pressure system of the fuel system for an internal combustion engine.

[0002] A vehicle powered by an internal combustion engine comprises a fuel system that supplies fuel from a fuel tank to the vehicle's internal combustion engine. The fuel system typically includes a low-pressure system designed to supply fuel from the fuel tank to an injection pump in a defined manner, particularly at a defined target pressure, enabling the injection pump to deliver a defined quantity of fuel to the internal combustion engine.

[0003] For further information on the state of the art, reference is made to DE 10 2010 027 677 B4, DE 10 2013 217 135 B4 and DE 10 2015 216 016 A1.

[0004] This document addresses the technical task of achieving efficient and reliable monitoring of the low-pressure system of a fuel system for an internal combustion engine, in particular to enable precise adjustment of the fuel-air mixture for the operation of the internal combustion engine.

[0005] The problem is solved by each of the independent claims. Advantageous embodiments are described, inter alia, in the dependent claims. It should be noted that additional features of a claim dependent on an independent claim, without the features of the independent claim itself or only in combination with a subset of the features of the independent claim, can constitute a separate invention independent of the combination of all features of the independent claim, which can be made the subject of an independent claim, a divisional application, or a subsequent application. This applies equally to technical teachings described in the description, which can constitute an invention independent of the features of the independent claims.

[0006] According to one aspect, a device for checking the low-pressure sensor of the low-pressure system of a fuel system for supplying fuel to an internal combustion engine (in particular a gasoline engine or a diesel engine) is described. The fuel system may have a fuel tank for receiving fuel. Fuel can be supplied from the fuel tank to the low-pressure system of the fuel system via a low-pressure pump. The actual fuel pressure can be adjusted to a specific target pressure (by operating the low-pressure pump). Furthermore, measured values ​​relating to the actual fuel pressure in the low-pressure system can be acquired using the low-pressure sensor.

[0007] The low-pressure system allows fuel to be supplied to a high-pressure pump at a specific target pressure, whereby the high-pressure pump can be configured to supply fuel at an increased pressure to the internal combustion engine, in particular to inject it into the internal combustion engine.

[0008] The device is designed to detect, based on a measurement signal from the low-pressure sensor, that a first criterion for the (possible) presence of an impairment of the low-pressure sensor is met. The measurement signal is preferably acquired during normal operation of the fuel system. The target pressure of the fuel in the low-pressure system can remain unchanged and / or constant during the acquisition period of the measurement signal. The measurement signal can comprise 50 or more, in particular 100 or more, measured values ​​for a corresponding sequence of successive time points. These time points can, for example, follow one another at a (constant) interval of 1 second or less, in particular 1 / 10 of a second or less.

[0009] The actual fuel pressure in the low-pressure system typically fluctuates around the target pressure. This fluctuation in the measured signal can be caused by the high-pressure pump of the fuel system, which is located downstream of the low-pressure system. The high-pressure pump can, for example, be operated at a specific pumping frequency, which causes fuel to surge back into the low-pressure system at that frequency. As a result, the actual pressure in the low-pressure system can fluctuate, with the oscillation having a frequency corresponding to the pumping frequency.

[0010] The device can be configured to analyze a vibration in the low-pressure sensor's measurement signal in order to verify the first criterion for the presence of a malfunction of the low-pressure sensor. In particular, to verify the first criterion, it can be checked whether the measurement signal exhibits a vibration that corresponds to the vibration of the actual pressure in the low-pressure system expected (due to the operation of the high-pressure pump).

[0011] The device can be configured, in particular, to determine an indicator of the strength, especially the amplitude, of the oscillation of the measurement signal. This can be achieved using a time-frequency transformation, especially a Fourier transform. The indicator of the strength of the oscillation of the measurement signal can, for example, be the magnitude of at least one transformation coefficient, especially a Fourier coefficient, at the frequency corresponding to the pump frequency of the expected oscillation of the actual pressure in the low-pressure system.

[0012] The first criterion for the presence of an impairment of the low-pressure sensor can be precisely verified based on the indicator for the strength of the vibration of the measurement signal, in particular by ensuring that • the first criterion is recognized as fulfilled if the indicator for the strength of the measurement signal oscillation indicates a strength of the measurement signal oscillation that is less than a predefined threshold; and / or • the first criterion is recognized as not being met if the indicator for the strength of the oscillation of the measurement signal indicates a strength of the oscillation of the measurement signal that is greater than the threshold.

[0013] It is therefore possible to check whether the measurement signal exhibits a sufficiently strong oscillation or not to verify the first criterion for the (possible) presence of an impairment of the low-pressure sensor.

[0014] The first criterion for the (possible) presence of a malfunction in the low-pressure sensor can be checked without causing a (dedicated) change to the target fuel pressure in the low-pressure system and / or without interfering with the operation of the fuel system. The first criterion can therefore be checked efficiently without having to specifically alter the normal operation of the fuel system to check the low-pressure sensor.

[0015] The device is further configured, in response to the detection that the first criterion is met, to verify, by means of a (dedicated) change in the target pressure of fuel in the low-pressure system, whether the low-pressure sensor is (actually) impaired. For this purpose, the low-pressure pump of the fuel system can be caused to change the actual pressure of fuel in the low-pressure system according to the predetermined change in the target pressure.

[0016] The device is preferably configured to effect the change in the target pressure of fuel in the low-pressure system for checking the low-pressure sensor only after it has been recognized that the first criterion is met.

[0017] By specifically changing the target pressure, a malfunction of the low-pressure sensor can be reliably detected. However, the target pressure is only changed if there is a suspicion of a malfunction (i.e., only if the first criterion is met). This allows the low-pressure sensor to be reliably monitored without significantly affecting the operation of the fuel system.

[0018] The device can be configured to detect changes in the readings of the low-pressure sensor resulting from a change in the target pressure of the fuel in the low-pressure system. For example, at least one reading before the change and at least one further reading after the change in the target pressure can be recorded to determine a change (e.g., a difference) in the readings of the low-pressure sensor.

[0019] It can then be reliably verified, based on the determined change in measured values ​​of the low-pressure sensor, and in particular based on a comparison of the determined change in measured values ​​of the low-pressure sensor with the resulting change in the setpoint pressure, whether the low-pressure sensor is impaired. In particular, it can be determined whether • the low-pressure sensor exhibits a malfunction such as sticking and / or a limitation of measured values; or • the low-pressure sensor shows no impairment, and instead the fuel in the low-pressure system shows bubbles, especially vapor bubbles.

[0020] The device can be configured, in particular, to determine that the low-pressure sensor is impaired (especially by sticking and / or limiting measured values) if the measured change in the low-pressure sensor readings is less than a change threshold. This change threshold typically depends on the resulting change in the setpoint pressure.

[0021] Furthermore, the device can be configured to determine that the low-pressure sensor is not impaired (and instead the fuel in the low-pressure system has bubbles, especially vapor bubbles) if the determined change in measured values ​​of the low-pressure sensor is greater in magnitude than the change threshold.

[0022] Changing the target pressure thus makes it possible to determine details regarding the condition of the low-pressure sensor and / or the low-pressure system.

[0023] The device can be configured to take at least one action relating to the internal combustion engine if it is determined that the low-pressure sensor is impaired. This action may include, for example, • issuing a warning to a user of the internal combustion engine; and / or • an adjustment, in particular a degradation, of the operation of the internal combustion engine.

[0024] This can ensure particularly reliable operation of the fuel system and / or the combustion engine.

[0025] According to another aspect, a fuel system for an internal combustion engine is described which includes the device described in this document.

[0026] According to another aspect, a (road) motor vehicle (in particular a passenger car or a truck or a bus or a motorcycle) is described that includes the device and / or the fuel system described in this document.

[0027] According to one aspect, a method for checking the low-pressure sensor of the low-pressure system of a fuel supply system for an internal combustion engine is described. The method includes detecting, based on a measurement signal from the low-pressure sensor (acquired during normal operation of the fuel system), that a first criterion for the presence of a malfunction of the low-pressure sensor is met. Furthermore, in response to the detection that the first criterion is met, the method includes checking, based on a change in the target pressure of fuel in the low-pressure system, whether the low-pressure sensor is malfunctioning.

[0028] It should be noted that the aspects described in connection with the device, in particular the claims described in connection with the device, are also applicable to the method as corresponding process features.

[0029] Another aspect described is a software (SW) program. The SW program can be configured to run on a processor (e.g., on a vehicle's control unit) and thereby execute the procedure described in this document.

[0030] Another aspect describes a storage medium. This storage medium can include a software program configured to run on a processor and thereby execute the procedure described in this document.

[0031] It should be noted that the methods, devices, and systems described in this document can be used both alone and in combination with other methods, devices, and systems described in this document. Furthermore, any aspect of the methods, devices, and systems described in this document can be combined with one another in a variety of ways. In particular, the features of the claims can be combined with one another in a variety of ways. Features listed in parentheses are to be understood as optional features.

[0032] The invention will now be described in more detail using exemplary embodiments. Fig. 1 Exemplary components of a fuel system for the provision of fuel to an internal combustion engine; Fig. 2a an exemplary time course (i.e. a measurement signal) of the pressure measured by a low-pressure sensor in the low-pressure system of a fuel system; Fig. 2b an exemplary frequency analysis of the pressure profile (i.e., the measurement signal) recorded by the low-pressure sensor; Fig. 3a an exemplary pressure curve measured by a non-impaired low-pressure sensor; Fig. 3b an exemplary pressure curve measured by a faulty low-pressure sensor; and Fig. 4 A flowchart of an exemplary procedure for monitoring the low-pressure sensor of a fuel system.

[0033] As stated at the outset, this document deals with the efficient and reliable monitoring of the low-pressure system of a fuel system for supplying fuel for the operation of an internal combustion engine, in particular an internal combustion engine of a motor vehicle. In this context, it shows Fig. Figure 1 shows an exemplary fuel system 100 for an internal combustion engine 110, which has a fuel tank 102 for receiving fuel 103. The fuel 103 can be supplied via a fuel line 104 to a fuel delivery pump 105 (i.e., a low-pressure pump) which is configured to adjust the actual pressure of the fuel 103 in the low-pressure system of the fuel system 100. The low-pressure system may, for example, include a fuel filter 106. Furthermore, the low-pressure system has a low-pressure sensor 107 which is configured to acquire sensor data relating to the actual pressure of the fuel 103 in the low-pressure system. The fuel delivery pump 105 can be operated depending on the sensor data from the low-pressure sensor 107 (e.g., by a control device 101) in order to adjust the actual pressure of the fuel 103 in the low-pressure system to a specific setpoint or target pressure.

[0034] The low-pressure system makes it possible to supply the fuel 103 to an injection pump 108 (i.e., a high-pressure pump) of the internal combustion engine 110 at a specific target pressure, so that the injection pump 108 can precisely adjust the fuel-air mixture for the operation of the internal combustion engine 110.

[0035] The low-pressure system of the internal combustion engine 110 or the fuel system 100 is thus responsible for fuel supply. The low-pressure system supplies the one or more downstream components of the injection system, e.g., a port fuel injection system or the high-pressure pump of a direct injection system, with fuel 103 that has the target pressure required by these components. A low-pressure sensor 107 can measure whether the set actual pressure of the fuel 103 corresponds to the target pressure. The correctly set actual pressure of the fuel 103 is typically crucial for the correct functioning of the components downstream of the low-pressure system and, in particular, for the correct adjustment of the fuel injection mass. For example, in a port fuel injection system, the injection time is typically determined as a function of the actual pressure of the fuel 103 in the low-pressure system.If the actual pressure measured by the low-pressure sensor 107 is higher than the actual pressure present in the low-pressure system, the injection time is too long and too much fuel 103 is injected, resulting in a rich fuel-air mixture for the operation of the internal combustion engine 110. Conversely, if the measured actual pressure is lower than the actual pressure present in the low-pressure system, the injection time is too short and too little fuel 103 is injected, resulting in a lean fuel-air mixture for the operation of the internal combustion engine 110. Both a rich and a lean fuel-air mixture typically lead to deterioration of the exhaust gas of the internal combustion engine 110.

[0036] A possible fault that can occur with the low-pressure sensor 107 is that the sensor's measurement signal becomes "stuck" at a fixed value. As a result, the low-pressure sensor 107 does not respond to any actual pressure changes in the low-pressure system. In other words, the "stuck" measurement signal of the low-pressure sensor 107 typically causes the sensor to output a constant measurement signal even when there is an actual pressure change in the low-pressure system.

[0037] The aforementioned fault pattern of the low-pressure sensor 107 can be identified based on the fact that, due to the injection and / or high-pressure pump 108 of the fuel system 100, a fluctuation in the actual pressure is typically present in the low-pressure system. This fluctuation is generated by the recoil of fuel 103 caused by the cams of the high-pressure pump 108. The presence of this fluctuation in the actual pressure in the low-pressure system can be used as an indicator of a functioning and / or undamaged low-pressure sensor 107. In the case of a "stuck," i.e., impaired, low-pressure sensor 107, there is typically no fluctuation in the measurement signal of the low-pressure sensor 107.

[0038] The (control and / or evaluation) device 101 can be configured to analyze the measurement signal of the low-pressure sensor 107 for the presence of vibration in order to determine whether or not the low-pressure sensor 107 is impaired. In particular, the amplitude of the vibration of the measurement signal from the low-pressure sensor 107 can be determined to ascertain whether or not impairment exists. For this purpose, the average amplitude of the vibration of the measurement signal from the low-pressure sensor 107 can be determined using a Fourier transform (especially at a frequency corresponding to the pumping frequency of the high-pressure pump 108). If the determined amplitude is less than a predefined amplitude threshold, it can be concluded that the low-pressure sensor 107 (may) be impaired.

[0039] Fig. Figure 2a shows an example measurement signal 202 of the low-pressure sensor 107, where the measurement signal 202 comprises a sequence of measured values ​​of the actual pressure 200 of the low-pressure system for a corresponding sequence of successive time points. The measurement signal 202 can contain measured values ​​with a specific sampling or measurement frequency. The sampling or measurement frequency can be 1 Hz or higher, or 10 Hz or higher. Furthermore, the measurement signal 202 can extend over a specific measurement and / or acquisition period, e.g., 10 seconds or more, or 30 seconds or more. As shown in Figure 2a, the measurement signal 202 can be measured at a specific sampling and / or acquisition time point. Fig. As can be seen in 2a, the measurement signal 202 of the actual pressure 200 shows an oscillation around the target pressure 201.

[0040] As already explained, the device 101 can be set up to operate the low-pressure pump 105 depending on the measuring signal 202 in order to adjust (in particular to regulate) the actual pressure 200 to the specified target pressure 201.

[0041] The measurement signal 202 can be transformed from the time domain to the frequency domain using a time-frequency transformation (e.g., using a Fourier transform), as exemplified in Fig. 2b shown. Fig. Figure 2b illustrates the magnitude 210 of a plurality of transformation coefficients 212, 213 (determined by time-frequency transformation) for a corresponding plurality of different frequencies. The plurality of transformation (in particular Fourier) coefficients 212, 213 typically includes a transformation coefficient 213 for zero frequency. This transformation coefficient 213 represents the target pressure 201 around which the measurement signal 202 oscillates.

[0042] Furthermore, the plurality of transformation coefficients 212, 213 exhibits one or more transformation coefficients 212 at a frequency corresponding to the (pump) frequency of the oscillation of the measurement signal 202 caused by the high-pressure pump 108. The (pump) frequency of the operation of the high-pressure pump 108 is typically known, so the expected frequency of the oscillation of the measurement signal 202 is also known. The magnitude 210 of the one or more transformation coefficients 212 for the one or more expected frequencies of the oscillation of the measurement signal 202 can be considered an indicator of the strength of the oscillation of the measurement signal 202 and can be compared with a predefined amplitude threshold 211 to detect any impairment of the low-pressure sensor 107. If the amount 210 is equal to or greater than the amplitude threshold 211, it can be concluded that there is no impairment of the low pressure sensor 107.If, on the other hand, the amount 210 is smaller than the amplitude threshold 211, it can be concluded that (possibly) there is an impairment of the low-pressure sensor 107.

[0043] Based on the analysis of the vibration of the measurement signal 202 of the low pressure sensor 107, it can thus be checked whether a first (error) criterion for the presence of an impairment of the low pressure sensor 107 is met or not.

[0044] It is possible for the fuel 103 in the low-pressure system to contain vapor bubbles. Vapor bubbles in the fuel 103 can dampen the oscillations of the fuel 103 in the low-pressure system, resulting in a relatively low amplitude oscillation of the measurement signal 202 from the low-pressure sensor 107. This can lead to the low-pressure sensor 107 being diagnosed as faulty due to the aforementioned (first) fault criterion, even though the low-pressure sensor 107 is not faulty.

[0045] A second, subsequent fault criterion can be used to check whether the low-pressure sensor 107, which was identified as possibly impaired (due to the first fault criterion), is actually impaired (and in particular “stuck”) or whether, alternatively, the low-pressure sensor 107 is not impaired (and in particular the fuel 103 has vapor bubbles).

[0046] To diagnose a "stuck" sensor 107, the oscillation of the measurement signal 202 can be analyzed in a first step to identify an initial fault criterion. This first fault criterion can then be confirmed if the second fault criterion is present, so that the sensor 107 can be reliably diagnosed as faulty.

[0047] As a second error criterion, it can be checked whether the measured value 200 of the low-pressure sensor 107 reacts to a change in the setpoint pressure 201 in the low-pressure system. The check of the second error criterion can be selectively triggered by the occurrence of the first error criterion. In particular, the check of the second error criterion can be selectively triggered if the average amplitude 210 of the oscillation of the measurement signal 202, determined from the Fourier transform, is below the amplitude threshold 211.

[0048] To verify the second fault criterion, the target pressure 201 for the low-pressure system can be increased. This increased target pressure 201 is typically achieved by increasing the pumping capacity of the low-pressure pump 105. Due to the increased pressure in the low-pressure system, a corresponding change in the measured values ​​200 of the low-pressure sensor 107 is expected. The detected change in the measured values ​​200 of the low-pressure sensor 107 can be compared with the requested change in the target pressure 201. If the detected change in the measured values ​​200 of the low-pressure sensor 107 is too low (compared to the requested change in the target pressure 201), it can be determined that the low-pressure sensor 107 is malfunctioning.If, on the other hand, the recorded change in the measured values ​​200 of the low-pressure sensor 107 matches the requested change in the target pressure 201, it can be determined that the low-pressure sensor 107 is not impaired, in particular it can be determined that the low-pressure sensor 107 is not “stuck”.

[0049] Fig. 3a and Fig. Figure 3b shows exemplary measurement signals 321, 322 of the low-pressure sensor 107, in the case that no impairment is present ( Fig. 3a) and in the event of an impairment ( Fig. 3b). The target pressure 201 for the low-pressure system is increased at a first time point 311 from a first value 301 to a second value 302, and can be reduced again at a second time point 312 from the second value 302 to the first value 301. In the Fig. In the example shown in 3a, the measurement signal 321 follows the change in the value 301, 302 of the target pressure 201, so that it can be determined that the low-pressure sensor 107 is not impaired. In the example shown in Fig. In the example shown in 3b, the measurement signal 322 remains essentially unchanged even when the value 301, 302 of the target pressure 201 is changed, and thus does not follow the change in the value 301, 302 of the target pressure 201. In this case, it can be determined that the low-pressure sensor 107 is impaired.

[0050] Fig.Figure 4 shows a flowchart of a (possibly computer-implemented) method 400 for checking the low-pressure sensor 107 of the low-pressure system of the fuel system 100 for supplying fuel 103 to an internal combustion engine 110. The fuel system 100 can have a low-pressure system (with a relatively low fuel pressure) configured to supply fuel at a defined setpoint pressure at the inlet of a high-pressure pump 108, the high-pressure pump 108 being configured to increase the fuel pressure, e.g., to inject fuel 103 into the internal combustion engine 110. The method 400 can be carried out by a control device 101 of the fuel system 100. The fuel system 100 and the internal combustion engine 110 can be part of a motor vehicle.

[0051] Method 400 comprises the detection 401, based on a measurement signal 202 from the low-pressure sensor 107, that a first criterion for the (possible) presence of an impairment of the low-pressure sensor 107 is met. The measurement signal 202 may have been acquired during the normal operation of the fuel system 100 (without the operation of the fuel system 100 being specifically adapted for checking the low-pressure sensor 107). The measurement signal 202 may exhibit a temporal sequence of measured values ​​200 from the low-pressure sensor 107 (e.g., 50 or more, or 100 or more measured values ​​200). As part of the verification of the first criterion, it can be checked whether the measurement signal 202 exhibits a sufficiently strong oscillation (possibly an oscillation with a defined (pump) frequency) or not.In particular, it can be checked whether the measurement signal 202 exhibits a vibration that correlates with the operation of the high-pressure pump 108 (especially whether it has a frequency that correlates with the pumping frequency of the high-pressure pump 108).

[0052] In a first step (especially without affecting the operation of the fuel system 100), it can therefore be checked using a first criterion whether there might be an impairment of the low pressure sensor 105.

[0053] Procedure 400 further comprises, in response to the detection 401 that the first criterion is met (in particular, only if it has previously been detected that the first criterion is met), checking 402, by means of a (dedicated) change in the target pressure 201 of fuel 103 in the low-pressure system, whether the low-pressure sensor 107 is (actually) impaired. A significant change in the target pressure 201 can be effected for the purpose of checking 402 (e.g., by 5% or more, or by 10% or more). The low-pressure pump 105 can then be caused to adjust the actual pressure in the low-pressure system according to the requested change in the target pressure 201.

[0054] It can then be checked, using the measured values ​​200 from the low-pressure sensor 107, whether the measured values ​​200 change in accordance with the requested change in the target pressure 201 or not. In the latter case, it can be concluded that there is actually a malfunction of the low-pressure sensor 107.

[0055] The measures described in this document can efficiently increase the robustness of the fault detection of the low-pressure sensor 107 of a fuel system 100 of an internal combustion engine 110. In particular, incorrect diagnoses can be avoided. Furthermore, a reliable distinction can be made between the cases of a "stuck sensor" and "vapor bubbles in the fuel".

[0056] The present invention is not limited to the embodiments shown. In particular, it should be noted that the description and the figures are intended only to illustrate the principle of the proposed methods, devices, and systems by way of example.

Claims

[1] Device (101) for checking a low-pressure sensor (107) of a low-pressure system of a fuel system (100) for supplying fuel (103) to an internal combustion engine (110); wherein the device (101) is configured, - to recognize, based on a measurement signal (202) from the low-pressure sensor (107), that a first criterion for the presence of an impairment of the low-pressure sensor (107) is fulfilled; and - in response to the recognition that the first criterion is met, to check whether the low pressure sensor (107) is impaired by means of a change in a target pressure (201) of fuel (103) in the low pressure system. [2] Device (101) according to claim 1, wherein - the device (101) is set up to analyze an oscillation of the measurement signal (202) of the low-pressure sensor (107) in order to verify the first criterion for the presence of an impairment of the low-pressure sensor (107); and - the oscillation of the measuring signal (202) is caused in particular by a high-pressure pump (108) of the fuel system (100) downstream of the low-pressure system. [3] Device (101) according to claim 2, wherein the device (101) is configured, - to determine an indicator (210) for a strength, in particular for an amplitude, of the oscillation of the measurement signal (202); and - to verify the first criterion for the existence of an impairment of the low-pressure sensor (107) on the basis of the indicator (210) for the strength of the oscillation of the measurement signal (202), in particular in such a way that - the first criterion is recognized as fulfilled if the indicator (210) for the strength of the oscillation of the measurement signal (202) indicates a strength of the oscillation of the measurement signal (202) that is less than a threshold value (211); and / or - the first criterion is recognized as not being met if the indicator (210) for the strength of the oscillation of the measurement signal (202) indicates a strength of the oscillation of the measurement signal (202) that is greater than the threshold (211). [4] Device (101) according to one of the preceding claims, wherein the device (101) is configured to check the first criterion for the existence of an impairment of the low-pressure sensor (107), - without causing a change in the target pressure (201) of fuel (103) in the low-pressure system; and / or - without interfering with the operation of the fuel system (100). [5] Device (101) according to one of the preceding claims, wherein the device (101) is configured, - to determine a change in measured values ​​(200) of the low-pressure sensor (107) caused by a change in the target pressure (201) of fuel (103) in the low-pressure system; and - based on the determined change in measured values ​​(200) of the low pressure sensor (107), in particular based on a comparison of the determined change in measured values ​​(200) of the low pressure sensor (107) with the resulting change in the target pressure (201), to check whether the low pressure sensor (107) is impaired. [6] Device (101) according to claim 5, wherein the device (101) is configured, - to determine that the low-pressure sensor (107) is impaired if the measured change in the readings (200) of the low-pressure sensor (107) is less than a change threshold value; wherein the change threshold value depends in particular on the change in the setpoint pressure (201); and / or - to determine that the low pressure sensor (107) is not impaired if the determined change in measured values ​​(200) of the low pressure sensor (107) is greater in magnitude than the change threshold. [7] Device (101) according to one of claims 5 to 6, wherein the device (101) is configured to determine, based on the determined change in measured values ​​(200) of the low-pressure sensor (107), in particular based on the comparison of the determined change in measured values ​​(200) of the low-pressure sensor (107) with the resulting change in the setpoint pressure (201), whether - the low-pressure sensor (107) exhibits a malfunction such as a jamming and / or a limitation of measured values ​​(200); or - the low pressure sensor (107) shows no impairment, and instead the fuel (103) in the low pressure system shows bubbles, especially vapor bubbles. [8] Device (101) according to one of the preceding claims, wherein the device (101) is configured to cause a low-pressure pump (105) of the fuel system (100) to change an actual pressure of fuel (103) in the low-pressure system according to the change in the target pressure (201). [9] Device (101) according to one of the preceding claims, wherein the device (101) is configured to effect the change in the target pressure (201) of fuel (103) in the low-pressure system for checking the low-pressure sensor (107) only after it has been recognized that the first criterion is met. [10] Device (101) according to any of the preceding claims, wherein - the device (101) is configured to take at least one action with respect to the internal combustion engine (110) when it is determined that the low-pressure sensor (105) is impaired; and - the measure in particular includes - issuing a warning to a user of the internal combustion engine (110); and / or - an adaptation, in particular a degradation, of the operation of the internal combustion engine (110). [11] Method (400) for checking a low-pressure sensor (107) of a low-pressure system of a fuel system (100) for supplying fuel (103) to an internal combustion engine (110); wherein the method (400) comprises, - Detect (401), based on a measurement signal (202) from the low-pressure sensor (107), that a first criterion for the presence of an impairment of the low-pressure sensor (107) is met; and - in response to the detection (401) that the first criterion is met, check (402) by means of a change in a target pressure (201) of fuel (103) in the low pressure system whether the low pressure sensor (107) is impaired.

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