Pollutant emission monitoring system for diesel engine of motor vehicle and associated method for detecting fault of system

Abstract

A method for detecting a malfunction of a pollutant emission control system (11) of an engine (1) equipped with a particulate filter (PF), comprising the steps of: determining a first maximum temperature at the filter inlet as a function of an instantaneous operating point of the engine; determining a second maximum temperature at the inlet of the filter from the first maximum temperature based on the measurement of the engine exhaust flow; determining a third maximum temperature at the filter inlet, the third maximum temperature corresponding to a minimum value between the second maximum temperature and a value of a temperature setpoint from a control device (14) of the system (11); calculating the deviation between the third maximum temperature and the temperature measurement value at the inlet of the filter; and detecting a fault of the control system when the calculated deviation exceeds a predetermined threshold deviation.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for monitoring a pollution emission control system of a compression ignition engine of a motor vehicle, in particular based on fault detection of the system. The invention also relates to a system implementing the method and to a motor vehicle equipped with the system or implementing the method. PRIOR ART

[0002] Despite the continuous development of the operating technology of internal combustion engines, in particular diesel engines, of motor vehicles, the engines still emit pollution particles, which consist of soot resulting from the incomplete combustion process of the engine.

[0003] According to the prior art, these particles present in the exhaust gases are trapped by a particle filter installed in the exhaust duct downstream of the combustion chamber of the engine. This filter is designed to retain the particles in the exhaust gases passing through the filter. With use of the engine, the particles accumulate in the filter, causing the exhaust back pressure to gradually increase, which is detrimental to the normal operation of the engine and to the fuel consumption.

[0004] To restore the optimal operating conditions of the engine, it is necessary to periodically regenerate the particle filter by burning the particles accumulated in the filter. This burning operation makes it possible to increase the internal temperature of the particle filter by increasing the temperature of the exhaust gases. This is generally done by delaying the injection of fuel into the combustion chamber of the engine. In particular, the fuel can be injected just after top dead center during the expansion phase, which has the effect of increasing the temperature of the exhaust gases.

[0005] The particle filter is therefore generally operated periodically in two phases. During the first phase, the filter stores the particles emitted by the engine; during the second phase, the particles stored in the filter are burned to regenerate the filter.

[0006] Generally, the regeneration of the particle filter is carried out periodically as soon as the mass of particles in the filter becomes too large. This regeneration is triggered automatically during operation of the engine. The particle filter is managed on the basis of a system for estimating the mass of particles present in the particle filter as a function of the differential pressure, also called differential pressure, across the filter, of the volume flow rate passing through the filter and of a model of operation of the filter.

[0007] However, the mass of particles in the filter can only be determined by the differential pressure and the volume flow rate during the first phase of storage of the particles. In fact, from the second phase, although the particle filter still contains a significant amount of soot, the burning of the soot causes the differential pressure to drop rapidly. The mass of soot can therefore not be estimated by the differential pressure during the second phase.

[0008] Thus, it is common to use a soot combustion model which is initialized at the beginning of the second phase with the soot mass value estimated from the pressure difference measured at the end of the first phase, and then to decrease this value progressively according to the current temperature, exhaust flow and oxygen concentration conditions.

[0009] The second phase is generally stopped in the case of a sufficient regeneration, i.e. when the soot combustion model indicates that the regeneration has successfully reduced the soot mass of the filter below a predetermined minimum mass threshold, except in the usual case where the driver switches off the engine.

[0010] In the case of an insufficient regeneration, the second phase is still stopped when a predetermined maximum regeneration time is reached. This insufficient regeneration is generally due to a too low temperature at the inlet of the filter, which does not allow the expected soot combustion. This too low temperature can result from a malfunction of the filter regeneration system (it is important to identify and correct this), but also simply from a vehicle operating condition, for example in the case of a long idle or very low speed operation. Despite a proper functioning of the system, this vehicle operating condition makes the temperature at the inlet of the filter insufficient for a sufficient regeneration of the filter.

[0011] Several solutions can be considered to identify a malfunction of the particulate filter regeneration system. However, these solutions are not satisfactory.

[0012] For example, it is not sufficient to count the frequency of regeneration of the particulate filter or the percentage of time spent in regeneration phase. Indeed, these criteria can be related to an abnormally high loading speed of the filter, which in turn depends on an increase in the particulate emissions of the engine, and not on a malfunction of the regeneration system.

[0013] It is also not ideal to compare the soot mass value from the soot combustion model at the end of the regeneration phase with the soot mass value obtained by pressure difference, since this only detects a deviation between the two models, without explicitly identifying a malfunction of the particulate filter regeneration system.

[0014] It is also not ideal to use a closed loop regulation of the temperature at the inlet of the particulate filter by monitoring the deviation of the loop, i.e. the difference between the temperature setpoint and the measured temperature, for the detection of a malfunction, since this mainly highlights the phases where the engine power required to reach the temperature necessary for soot combustion is insufficient. SUMMARY

[0015] The aim of the present invention is to achieve a reliable detection of a malfunction of the particulate filter regeneration system by excluding the cases of insufficient regeneration efficiency related to a vehicle operating condition.

[0016] The present invention relates to a method for detecting a malfunction of a pollution emission control system of a diesel engine of a motor vehicle equipped with a particulate filter.

[0017] The method comprises the following steps:

[0018] - determining a first maximum temperature at the filter inlet as a function of the instantaneous operating point of the engine;

[0019] - determining a second maximum filter inlet temperature as a function of the first maximum temperature, based on a measured value of the engine exhaust flow rate;

[0020] - determining a third maximum temperature at the filter inlet, corresponding to the minimum between the second maximum temperature and a value of a temperature setpoint from the control system device;

[0021] - calculating a deviation between the third maximum temperature and the filter inlet temperature measurement;

[0022] - detecting a control system failure when the calculated deviation exceeds a predetermined threshold deviation.

[0023] This method makes it possible to achieve reliable detection of a control system failure by excluding the case of insufficient regeneration due to operating conditions.

[0024] According to one feature, the method also comprises a time calculation step in which a total failure time is calculated, the total failure time representing the sum of the time periods elapsed each time from the detection of a failure to the moment when the calculated deviation is less than or equal to the predetermined threshold deviation.

[0025] For example, the method also comprises a step of sending a message or an alarm signal when the total failure time exceeds a predetermined threshold duration.

[0026] According to another feature, the method also comprises a step of calculating a total enthalpy deficit received by the filter, in which, for each time period elapsed from the detection of a failure to the moment when the calculated deviation is less than or equal to the predetermined threshold deviation, the sum of each integral of the product of the exhaust flow rate and the difference between the calculated deviation and the predetermined threshold deviation with respect to time is calculated.

[0027] For example, the method also comprises a step of sending a message or an alarm signal when the total enthalpy deficit received by the filter exceeds a predetermined threshold enthalpy deficit.

[0028] According to another aspect, the application relates to a control system for the pollution emissions of a motor vehicle diesel engine equipped with a particulate filter, comprising:

[0029] - a measurement device which measures the engine exhaust flow rate, the volumetric flow rate through the filter, the differential pressure between the inlet and outlet ends of the filter and the temperature at the filter inlet;

[0030] - a calculation device which is able to estimate the soot mass of the filter as a function of the information from the measurement device;

[0031] - a control device configured to control the regeneration of the particulate filter when the estimated soot mass of the filter exceeds a predetermined threshold mass.

[0032] According to one feature, the control system comprises: means for determining a first maximum temperature at the inlet of the filter as a function of the instantaneous operating point of the engine; means for determining a second maximum temperature at the inlet of the filter from the first maximum temperature and a measured value of the exhaust flow rate of the engine; and means for determining a third maximum temperature at the inlet of the filter, the third maximum temperature corresponding to the minimum between the second maximum temperature and a value of a temperature setpoint required by the control device for regenerating the filter.

[0033] Advantageously, the calculation device is configured to calculate a deviation between the third maximum temperature and the temperature measured at the inlet of the filter, and to detect a malfunction of the control system when the calculated deviation exceeds a predetermined threshold deviation.

[0034] For example, the calculation device is configured to calculate a total malfunction time, the total malfunction time representing the sum of the time periods elapsed each time from the detection of a malfunction to the moment when the calculated deviation is less than or equal to the predetermined threshold deviation.

[0035] For example, the calculation device is configured to calculate a total enthalpy received by the filter, the total enthalpy received by the filter representing the sum of each integral over time of the product of the exhaust flow rate and the difference between the calculated temperature deviation and the predetermined threshold deviation for each time period elapsed from the detection of a malfunction to the moment when the calculated deviation is less than or equal to the predetermined threshold deviation.

[0036] Preferably, the control system comprises means for sending a message or an alarm signal.

[0037] According to another aspect, the application relates to a motor vehicle equipped with a diesel-type internal combustion engine, implementing the method described above or equipped with the pollution emission control system described above. BRIEF DESCRIPTION OF DRAWINGS

[0038] Other objects, characteristics and advantages of the application will become apparent from reading the following description, given only by way of non-limiting example, and with reference to the attached drawings, in which:

[0039] Figure 1 An exemplary application of the application is illustrated;

[0040] Figure 2 The evolution over time of the plurality of temperatures at the inlet of the particulate filter according to the application is illustrated;

[0041] Figure 3 The calculation of the total malfunction time according to an embodiment of the application is illustrated;

[0042] Figure 4 The calculation of the total enthalpy difference received by the particulate filter is shown;

[0043] Figure 5 A flowchart of a fault detection method for a pollutant emission control system according to the present invention is shown;

[0044] Figure 6 A flowchart of a fault detection method according to an embodiment of the present invention is shown;

[0045] Figure 7 A flowchart of a fault detection method according to an embodiment of the present invention is shown. Detailed description of at least one embodiment

[0046] Figure 1 The application of the invention to a vehicle internal combustion engine (here, a diesel engine) is shown in a non-limiting manner.

[0047] Engine 1 typically includes a fresh air intake manifold 2, which connects to both cylinders (three in the example shown) and a butterfly housing 3, allowing for regulation of the amount of fresh air entering the engine. The butterfly housing 3 is connected to the fresh air intake port via at least one pipe 4.

[0048] Engine 1 is provided with an exhaust pipe including an exhaust manifold 5, which is connected to a cylinder on one side and an exhaust port on the other. The exhaust pipe includes a filter marked PF. The PF filter is associated with a differential pressure sensor (not shown) that is capable of measuring the pressure difference ΔP between the filter inlet and outlet.

[0049] Engine 1 also includes a partial exhaust gas recirculation system at the engine intake, called the EGR circuit (an abbreviation for "Exhaust Gas Recycling"). This system allows a portion of the exhaust gas to be drawn from the exhaust pipe downstream of the particulate filter PF and recirculated back into the intake pipe after its temperature is reduced by the heat exchanger 6. The EGR circuit is equipped with an EGR valve 7 for controlling the flow of recirculated gas.

[0050] exist Figure 1 In the illustrated embodiment, engine 1 is equipped with a turbocharger 8. The compressor section 8a of the turbocharger 8 is arranged in the fresh air intake manifold upstream of the disc housing 3 to increase the fresh air supply pressure of engine 1. The turbine section 8b is arranged in the exhaust manifold to be driven by exhaust gases. If the EGR circuit is arranged upstream of the compressor 8a and downstream of the turbine 8b, the EGR circuit can be at a low pressure (e.g., Figure 1The EGR circuit can be at high pressure if it is arranged downstream of the compressor 8a and upstream of the turbine 8b.

[0051] In view of the presence of such an EGR circuit, the engine butterfly housing 3 is used to regulate the total intake flow of the engine, including the fresh air flow and the recirculated gas flow.

[0052] The flow of recirculated gas can be regulated by the EGR valve 7, then the air flow into the engine is obtained indirectly by the difference. In a variant, the air flow can also be regulated separately and directly by regulating the intake valve 9 of the intake circuit, to obtain the desired flow setpoint. Then, the flow of recirculated gas is obtained indirectly by the difference between the total flow and the fresh air flow.

[0053] The total flow of gas into the engine is obtained by regulating the value of the prevailing pressure in the intake manifold 2 of the engine 1, taking into account the temperature and the filling model.

[0054] To achieve this, a pressure sensor 2a and a temperature sensor 2b are provided in the intake manifold 2. The pressure is regulated by adjusting the position of the butterfly housing 3.

[0055] In the case of an engine without EGR circuit (not shown), there is usually only one butterfly housing 3 to regulate the only gas flow into the engine, i.e. the fresh air flow. There is no intake valve 9.

[0056] The engine 1 is equipped with a control system 11 of the engine pollution emissions. The control system 11 comprises measuring means 12, calculating means 13 and control means 14.

[0057] The measuring means 12 are configured to measure operating parameters of the engine, in particular parameters related to the flow, temperature and pressure in the intake and exhaust circuits of the engine.

[0058] The calculating means 13 are configured to estimate the soot mass of the PF filter from the information from the measuring means 12.

[0059] The control means 14 are configured to control the regeneration of the PF filter when the estimated soot mass of the filter exceeds a predetermined threshold mass. The control means 14 usually comprise a temperature regulator at the inlet of the PF filter, configured to control the settings of the motor according to a temperature setpoint Tcs required for regenerating the filter (for example depending on the mass contained in said filter).

[0060] The control system 11 also comprises a storage module (not shown).

[0061] The control system 11 comprises means for determining a first maximum temperature T1, means for determining a second maximum temperature T2 and means for determining a third maximum temperature T3.

[0062] The first maximum temperature T1 at the inlet of the PF filter is determined from a predetermined map available in a memory module of the system, as a function of the instantaneous operating point of the engine.

[0063] For example, this map associates each operating point of the engine 1 with a maximum temperature at the inlet of the PF filter, taking into account the values of the engine's regulation parameters, such as the injection phase in advance or in delay and the injection flow rate. This map can be obtained by an identification procedure performed in particular after a preliminary stabilization phase on an engine test bench.

[0064] The first maximum temperature T1 represents an estimate of the maximum temperature that can be reached at the inlet of the PF filter by any engine free of defects, including discrete engines, i.e. including components at the limit of their production tolerances.

[0065] However, it takes a sufficiently long time to reach the first maximum temperature T1, taking into account the dynamic characteristics of the temperature regulator and the thermal inertia of the exhaust circuit, related to its mass.

[0066] It is therefore necessary to filter the first maximum temperature T1, for example as a function of a measured value of the engine exhaust flow rate, in order to determine a second maximum temperature T2, which represents the maximum filtering temperature that can be reached at the inlet of the PF filter by any engine free of defects at the current operating point of the engine, at each instant of regeneration of the particulate filter.

[0067] The second maximum temperature T2 can exceed the temperature setpoint Tcs required for regenerating the filter at the inlet of the PF filter.

[0068] It is therefore necessary to determine a third maximum temperature T3 at the inlet of the PF filter, which corresponds to the minimum between the second maximum temperature T2 and the value of the temperature setpoint Tcs required by the control means 14 for regenerating the filter.

[0069] The third maximum temperature T3 represents an estimate of the temperature that can be achieved and that is actually reached at the inlet of the PF filter by an engine free of faults.

[0070] In other words, whatever the operating point of the engine or the operating conditions of the vehicle, the third maximum temperature T3 is an estimate of the temperature at the inlet of the PF filter that can be reached by an engine free of faults.

[0071] Figure 2The evolution over time of the first maximum temperature T1, the second maximum temperature T2 and the third maximum temperature T3 is shown according to the operating conditions of the vehicle speed 15 illustrated in parallel. In this graph, the curve 16 and the curve 17 represent respectively the temperature measured at the PF filter inlet and the temperature setpoint Tcs required by the control device 14.

[0072] The computing device 13 is configured to calculate the deviation between the third maximum temperature T3 and the temperature measurement 16 at the PF filter inlet.

[0073] The computing device 13 is configured to detect a malfunction of the control system when the calculated deviation exceeds a predetermined threshold deviation, in particular during a predetermined abnormal high duration.

[0074] Thus, by excluding the cases of insufficient regeneration efficiency related to the operating conditions of the vehicle, and thus the cases of engine operating points for which the required temperature Tcs at the inlet of the particulate filter cannot be reached at all, it is possible to detect a malfunction of the engine pollutant emission control system.

[0075] In one embodiment, the computing device 13 is configured to calculate a total malfunction time, which represents the sum of the time periods elapsed between each time a malfunction is detected and the time at which the calculated deviation is less than or equal to the predetermined threshold deviation.

[0076] Figure 3 The calculation of the total malfunction time is illustrated.

[0077] In the attached figures, identical references are used to designate identical elements.

[0078] In Figure 3 In the example illustrated, the curve 19 is offset with respect to the curve T3 by a temperature value or safety margin 18, which represents the measurement and modelling errors and is equal to the predetermined threshold deviation. The curve 20 illustrates the variation of the total malfunction time. It should be noted that the total malfunction time increases when the temperature measured at the PF filter inlet (represented by the curve 16) is less than the corresponding value of the curve 19. In other words, the total malfunction time at a given time represents the sum of all the times during which the deviation between the temperature measured at the PF filter inlet and the third maximum temperature T3 is greater than the safety margin 18.

[0079] In another embodiment, the computing device 13 is configured to calculate a total enthalpy difference received by the PF filter, which represents the sum of each integral of the instantaneous exhaust flow rate multiplied by the difference between the calculated deviation and the predetermined threshold deviation with respect to time for each time period elapsed between the detection of a malfunction and the time at which the calculated deviation becomes less than or equal to the predetermined threshold deviation again.

[0080] Figure 4The calculation of the total enthalpy difference received by the PF filter is shown. Curve 21 represents the variation of the total enthalpy difference received by the PF filter. The total enthalpy difference corresponds to the sum of each integral of the instantaneous exhaust flow rate with respect to time, multiplied by the deviation between curve 19 and curve 16, for each time period elapsed between the moment when a fault is detected and the moment when the calculated deviation is again less than or equal to the predetermined threshold deviation. For ease of calculation, each zone 22 can be discretized into time intervals small enough so that, within each interval, the exhaust flow rate can be considered constant.

[0081] Alternatively, the calculation device 13 can still be configured to calculate both the total enthalpy difference received by the filter and the total fault time.

[0082] When the total fault time exceeds a predetermined threshold duration and / or when the total enthalpy difference received by the filter exceeds a predetermined threshold enthalpy difference, the control system 11 comprises a device for sending a message or an alarm signal.

[0083] The method for detecting a fault of a pollutant emission control system according to the application is represented by the flowchart shown. Figure 5

[0084] In a first step 23, a first maximum temperature T1 at the inlet of the PF filter is determined from a predetermined map available in the control system storage module, as a function of the instantaneous operating point of the engine. The operating point generally corresponds to parameters representative of the engine operating state, such as the speed and the load. The determination of the operating point is generally available from a high-level control unit (not marked).

[0085] In a second step 24, a second maximum temperature T2 at the inlet of the filter is determined from the first maximum temperature T1, as a function of a measured value of the engine exhaust flow rate, taking into account the thermal inertia of the exhaust circuit.

[0086] In a third step 25, a third maximum temperature T3 at the inlet of the filter is determined, which corresponds to the minimum between the second maximum temperature T2 and the value of the temperature setpoint Tcs from the control device 14 of the system 11.

[0087] The method continues with a step 26 of calculating the deviation between the third maximum temperature T3 and the temperature measurement at the inlet of the filter.

[0088] In a next step 27, it is determined whether the calculated deviation exceeds a predetermined threshold deviation.

[0089] If yes, a fault of the control system is detected (step 28). The method then returns to the first step 23.

[0090] If no, the method returns to the first step 23.

[0091] ​The sequence of steps 23 to 28, labelled 29, enables monitoring of the normal operation of the control system.

[0092] As shown in Figure 6 The method can comprise a time calculation step 30 of calculating a total failure time, representing the sum of the time periods elapsed each time from the detection of a failure to the moment when the calculated deviation is less than or equal to the predetermined threshold deviation time.

[0093] In a next step 31, it is determined whether the total failure time exceeds a predetermined threshold duration. It is noted that if the regeneration of the particulate filter is interrupted, for example by engine shutdown, the time threshold can be adjusted in combination with the temperature deviation so as to adapt to the actual regeneration consumption time.

[0094] If yes, the method continues with a step 32 of sending a message or an alarm signal for alerting the driver of a system failure.

[0095] If no, the process returns to step 23.

[0096] As shown in Figure 7 The method can comprise a step 33 of calculating a total enthalpy difference received by the filter, wherein for each time period elapsed from the detection of a failure to the moment when the calculated deviation is less than or equal to the predetermined threshold deviation, the sum of the product of the exhaust flow rate and each integral of the difference between the calculated deviation and the predetermined threshold deviation with respect to time is calculated.

[0097] In a next step 34, it is determined whether the total enthalpy difference received by the filter exceeds a predetermined threshold enthalpy difference. It is noted that if the regeneration of the particulate filter is interrupted, for example by engine shutdown, the enthalpy difference threshold can be adjusted to adapt to the actual regeneration consumption time.

[0098] If yes, the method continues with a step 32 of sending a message or an alarm signal for alerting the driver of a system failure.

[0099] If no, the process returns to step 23.

[0100] As a variant, the method can still perform in parallel the time calculation step 30 and the total enthalpy difference received calculation step 33, and steps 31 and 34 can be combined.

[0101] As a variant, the step 32 of sending a message or an alarm signal can still be performed immediately after the step 28 of detecting a failure.

Claims

1. A method for detecting a fault in a pollution emission monitoring system (11) of a diesel engine (1) of a motor vehicle equipped with a particulate filter (PF), characterized in that, Includes the following steps: - Determine the first maximum temperature (T1) at the inlet of the filter (PF) based on the instantaneous operating point of the engine (1). -Based on the measured value of the exhaust flow of the engine (1), the second maximum temperature (T2) at the inlet of the filter (PF) is determined by the first maximum temperature (T1). - Determine the third maximum temperature (T3) at the inlet of the filter (PF), the third maximum temperature (T3) corresponding to the minimum value between the second maximum temperature (T2) and the temperature setpoint (Tcs) from the control device (14) of the system (11); - Calculate the deviation between the measured value of the third highest temperature (T3) and the filter inlet temperature (PF); - When the calculated deviation exceeds a predetermined threshold deviation, a fault in the control system (11) is detected.

2. The method according to claim 1, further comprising a time calculation step, wherein the total failure time is represented as the sum of the time elapsed between each failure detection and the calculated deviation being less than or equal to the predetermined threshold deviation time.

3. The method according to claim 2, further comprising the step of sending a message or alarm signal when the total failure time exceeds a predetermined threshold duration.

4. The method of claim 1, further comprising the step of calculating the total enthalpy difference received by the filter (PF), wherein for each time elapsed between the detection of a fault and the time elapsed between the calculated deviation being less than or equal to the predetermined threshold deviation, the sum of each time integral of the product of the exhaust flow rate and the difference between the calculated deviation and the predetermined threshold deviation is calculated.

5. The method of claim 4, further comprising the step of sending a message or alarm signal when the total enthalpy difference received by the filter exceeds a predetermined threshold enthalpy difference.

6. A control system (11) for pollution emissions from a diesel engine (1) of a motor vehicle equipped with a particulate filter (PF), comprising: - Measuring device (12) for measuring the exhaust flow rate of the engine, the volumetric flow rate through the filter, the pressure difference between the inlet and outlet of the filter, and the temperature at the inlet of the filter; - The computing device (13) is capable of estimating the mass of the filter dust based on information from the measuring device; The control device (14) is configured to control the regeneration of the particulate filter when the estimated dust mass of the filter exceeds a predetermined threshold mass; Its features include: -A device for determining the first maximum temperature (T1) at the inlet of the filter (PF) based on the instantaneous operating point of the engine (1); - A means for determining a second maximum temperature (T2) at the inlet of the filter (PF) based on a measurement of the exhaust flow rate of the engine (1) and the first maximum temperature (T1); and - A device for determining a third maximum temperature (T3) at the inlet of the filter (PF), the third maximum temperature (T3) corresponding to the minimum value between the second maximum temperature (T2) and the value of the temperature setpoint required by the control device (14) for regenerating the filter; The computing device (13) is configured to calculate the deviation between the measured value of the third highest temperature (T3) and the temperature at the filter inlet, and is configured to detect a fault in the control system (11) when the calculated deviation exceeds a predetermined threshold deviation.

7. The system according to claim 6, wherein, The computing device (13) is configured to calculate the total failure time, which represents the sum of the time elapsed between each failure detection and the calculated deviation being less than or equal to the predetermined threshold deviation time.

8. The system according to claim 6, wherein, The computing device (13) is configured to calculate the total enthalpy difference received by the filter (PF), which represents the sum of the product of the exhaust flow rate and the difference between the calculated deviation and the predetermined threshold deviation with respect to each time interval elapsed from the detection of a fault to the time elapsed when the calculated deviation is less than or equal to the predetermined threshold deviation.

9. The system according to any one of claims 6 to 8, comprising means for transmitting messages or alarm signals.

10. A motor vehicle equipped with a diesel internal combustion engine (1), which implements the method according to any one of claims 1 to 5 or is equipped with a pollutant emission control system (11) according to any one of claims 6 to 9.

Images