Abstract: Methods and systems are provided for learning characteristics of a road segment and using the learning during a subsequent travel on the road segment to preview the road segment and schedule diagnostic routines to increase in-use monitor performance (IUMP) rates for vehicle system diagnostics. In one example, a method may include scheduling a diagnostic routine for an engine sub-system based on the learned characteristics of the road segment, and a variable adjustable based on IUMP rate.

Abstract: A diagnostic device is configured to execute a first acquisition process of acquiring a remaining amount of evaporated fuel in a fuel tank when an ignition switch turns off, as an end remaining amount, a determination process of, after the first acquisition process, determining whether there is a blockage of a vapor passage by reducing a pressure in a vapor passage with a pressure reducing pump when the end remaining amount is smaller than a prescribed value while the ignition switch is off, a second acquisition process of, after the determination process, acquiring a remaining amount of liquid fuel in the fuel tank when the ignition switch turns on, as a start remaining amount, and an invalidation process of invalidating a determination result that a blockage is present in the vapor passage in the determination process when the start remaining amount is larger than or equal to a set value.

Abstract: A vehicle fuel system includes a turbocharger having a compressor disposed on an intake line of an engine. The compressor selectively compresses intake air supplied to the engine. The fuel system has a canister configured to capture fuel vapor discharged from a fuel tank and a purge control valve configured to open or close the purge line depending on a pressure of the intake line. The fuel system has a check valve provided on the purge line that blocks movement of a fluid from the intake line to the canister. The fuel system has a controller performing control such that the purge control valve is operated in a closed mode to prevent intake air in the intake line from being introduced into the fuel tank when breakdown of the check valve is sensed during driving of the vehicle.

Abstract: A failure diagnostic device is configured to determine saturated vapor pressures of a fuel within a fuel tank. In a fuel vapor processing apparatus, some or all of the passages and spaces into which the fuel vapor flows into the fuel vapor processing apparatus are closed to the atmosphere. In this condition, the failure diagnostic device determines a plurality of saturated vapor pressure characteristics over time. The failure diagnostic device is configured to diagnose whether or not a leakage or a blockage failure in the fuel vapor processing apparatus is present. The failure diagnostic device determines a Reid vapor pressure (RVP) based on each of the plurality of determined saturated fuel vapor pressure characteristic and diagnoses whether or not a failure is present in accordance with a change in these RVPs over time.

Abstract: A method of controlling an evaporative emissions system for a vehicle is provided. A fuel system for a vehicle and a vehicle are also provided. A signal indicative of an entry condition associated with a secondary air flow path for a purge of an evaporative emissions canister is received. A filter is decoupled from a port of the evaporative emissions canister in response to receiving the signal and prior to the evaporative emissions canister purge. The evaporative emissions canister is purged by flowing atmospheric air into the port and through the evaporative emissions canister while the filter is decoupled from the port. The filter is coupled to the port of the evaporative emissions canister after purging the canister.

Abstract: Methods and systems for diagnosing operation of an evaporative emissions system are described. The methods and systems may include increasing an amount of vacuum stored in an evaporative emissions system during discontinuously operating an engine in a boosted operating mode. Storing vacuum allows the evaporative emissions system to reach a desired vacuum level to verify absence of an evaporative emissions system breech.

Abstract: A leak hole determination device in an evaporated fuel processing system. The leak hole determination device includes: a first pressure detector for detecting a first pressure in a fuel tank; a second pressure detector for detecting a second pressure in a canister; and a leak hole determiner for determining whether a leak hole is present. The leak hole determiner determines, after a limit pressure timing subsequent to a depressurization operation for depressurizing an inside of the system, whether a leak hole is present by using a difference between a change speed of a first pressure detected by the first pressure detector and a change speed of a second pressure detected by the second pressure detector.

Abstract: Provided is a diagnosis device for an internal combustion engine where the internal combustion engine includes a blow-by gas passage through which blow-by gas flows and the diagnosis device includes a temperature sensor which detects a temperature inside the blow-by gas passage and an abnormality detection unit which detects an abnormality in the internal combustion engine based on a detected value of the temperature sensor.

Abstract: Methods and systems for performing diagnostics on an evaporative emission are described. The methods and systems may include evaluating pressure or vacuum development within an evaporative emissions system over time to determine the presence or absence of a breach in the evaporative emissions system. If a breach is identified, mitigating actions may be performed.

Abstract: A module (49, 149, 249) for use in a vehicle fuel system, said module comprising a housing (7) having a first port (9), a second port (41) and a passage (57) between the first port and the second port; a closure body (11) that is moveably arranged in said housing; wherein said closure body is configured for closing the passage between the first port and the second port in a first position of the closure body and for allowing access to the passage in a second position of the closure body; and a pump (13) that is integrated in said housing (7), wherein said pump (13) communicates with the first port (9) and is configured for pumping fluid into or out of the first port (9) while the closure body (11) is in the first position, characterized in that the module (49, 149) further comprises a motor (15) and a closure body actuator (67) configured for positioning the closure body (11, 111) in at least the first position and the second position, wherein said closure body actuator is driven by said motor (15), and said

Abstract: An vapor purge system for a turbocharged internal combustion engine having an evaporative emissions turbo purge valve incorporating a venturi vacuum generator and a hose-off detection function. The turbo purge valve includes a pressure sensor, and a low restriction check valve which is integrated into the outlet port of the venturi vacuum generator. The pressure sensor is capable of detecting the small pressure drop (i.e., vacuum) generated at the air inlet tube or air box during naturally aspirated conditions. The check valve closes the venturi vacuum generator on the purge side during naturally aspirated conditions, allowing fluid communication to the air intake system through one port only, and the detection of the vacuum during these conditions. If a hose becomes detached, either at the outlet port of the venturi vacuum generator or at the air box, the small vacuum is not detected, and the ECU then diagnoses the hose-off condition.

Abstract: A blockage detection device opens a purge valve in a state where a negative pressure pump is operated. The negative pressure pump is connected to a downstream side of a canister with respect to a fuel tank, and reduces pressure in a device internal space. The blockage detection device calculates gas information (volume V, for example) of the device internal space on the basis of variation of internal pressure before and after the purge valve is opened. The blockage detection device detects a blockage in a vent line using the calculated gas information.

Abstract: An internal combustion engine has a tank ventilation system and a crankcase ventilation system. The tank ventilation system is connectable to an intake system downstream of a throttle element via a first non-return valve in a first line and upstream of a compressor via a second non-return valve in a second line and a third non-return valve in a second sub-line. The crankcase ventilation system is connectable to the intake system downstream of the throttle element via a fourth non-return valve in a third line and upstream of the compressor via a fourth line and the third non-return valve. The intake system is connectable to the second line downstream of the throttle element at a transitional point between the second line and the second sub-line via a fifth nonreturn valve in a fifth line. A nozzle is formed at the transitional point from the fifth line to the second line and the second sub-line, and the second line opens into the nozzle downstream of the second non-return valve.

Abstract: When the internal combustion engine is stopped, a pressure reduction pump performs a pressure reduction while a first open/close valve and a second open/close valve are closed. After that, a control unit determines whether a fault occurs in a second purge pipe between the second open/close valve and an intake pipe based on a measured value obtained by an obtaining portion immediately after the second open/close valve is opened.

Abstract: A purge system malfunction diagnosis device is configured to diagnose a malfunction in a purge system mounted on a vehicle. The purge system includes a canister, a purge passage, a purge valve capable of opening and closing the purge passage, an outside air passage configured to cause the canister to communicate with an outside air opening, an outside air valve capable of opening and closing the outside air passage, and a system pressure sensor configured to detect a pressure in the purge system. In a state where the outside air passage is closed, a diagnosis mode is executed on a basis of a relationship between the pressure in the purge system and an integrated value of flow rate estimates of a purge gas. In the diagnosis mode, a parameter to be used for diagnosing a malfunction in the purge system is adjusted in a case where the flow rate estimate is lower than a flow rate threshold.

Abstract: A method for diagnosing leakage of a fuel vapor dual purge system is provided. The method includes determining whether an operation region of a vehicle is an operation region in which a turbocharger is operated and adjusting a flow amount of intake air flowing into the turbocharger according to an operation region in which the turbocharger is operated. A hydrocarbon collecting amount of a canister connecting fuel vapor generated in the fuel tank is calculated and a flow amount of the fuel vapor passing first and second purge lines is adjusted. A leak of the fuel vapor is diagnosed in the first purge line and the second purge line.

Abstract: A vehicle may include a control module and a plurality of vehicle control modules in networked communication with the control module. The control module may be configured to receive an indication from a user interface to transition the vehicle into an extended park mode, and responsive to the indication, instruct the plurality of vehicle control modules to perform operations to reduce their respective key-off loads on the vehicle. A cloud service may be configured to receive, over a wide-area network responsive to user input to a mobile device, an indication to transition a vehicle associated with the mobile device into an extended park mode, and responsive to the indication, provide a message over the network to the vehicle to instruct the vehicle to perform operations to reduce key-off loads of a plurality of vehicle control modules of the vehicle.

Abstract: An evaporative fuel treatment apparatus includes a canister, a vapor passage, an outside air introduction passage, a purge passage that connects the canister and an intake passage to each other, a sealing valve configured to open/close a flow channel of the vapor passage, a tank internal pressure sensor, a pressure sensor configured to detect a vapor pressure; and an electronic control unit. The electronic control unit is configured to determine whether or not there is an abnormality in the tank internal pressure sensor based on a change in the vapor pressure in changing over the sealing valve from a closed state to an open state, when an amount of change in the tank pressure in changing over the sealing valve from the closed state to the open state is lower than a first predetermined value.

Abstract: A blockage determination portion 174 of a blockage detection system 30 determines that no blockage has occurred in a purge line 90, if a flow rate V of an inner fluid Fi exceeds a flow rate threshold THv while an internal pressure Pi of the purge line 90 is reduced from a first pressure value P1 to a second pressure value P2, for example. The blockage determination portion 174 determines that a blockage has occurred in the purge line 90, if the flow rate V of the inner fluid Fi falls below the flow rate threshold THv after the internal pressure Pi is reduced from the first pressure value P1 to the second pressure value P2.

Abstract: A method for improving reliability of an integrity or leak test includes determining at least one first parameter indicative of: a first volume of a sample, a first temperature of the sample, a first pressure of the sample and/or a first assessment of integrity of the sample. The method further determines at least one second parameter indicative of a deviation from the first parameter and at least one third parameter indicative of a second assessment of the integrity of the sample. The second assessment provides an indication of a passed or failed test. The method further determines whether the deviation has an impact on the indication of the second assessment. When the deviation is determined to have an impact on the indication of the second assessment, the method comprises identifying a possibility that the indication of the second assessment is incorrect.

Abstract: A computer-implemented platform may comprise hardware and software configured to estimate knock intensity and/or manage an engine using knock intensity data. A plurality of knock indicators may be used to model a knock response, providing an improved estimate of knock intensity. Knock intensities from a plurality of combustion cycles may be used to estimate a statistical distribution of knock intensities. The statistical distribution may be used to determine an engine tune state. An engine tune state may be modified via the incorporation of prior knock intensity statistics.

Abstract: A computer for a vehicle is programmed to receive fuel level data over a period of time during a refueling operation. Based on the fuel level data, the computer determines that fuel flow rate during one portion of the refueling operation is materially reduced relative to other portions of the refueling operation. The computer is programmed to output a failure mode based on the determination.

Abstract: The present invention relates to a method for determining a flow rate (Q) through an on-off valve (1) controlled by means of a pulse width modulated control signal (C) comprising a period (c) of updating the control signal and a control cycle (D), characterized in that, said control signal updating period (c) being a divisor of said control cycle (D), said method of determination comprises a determination period (d), the determination period (d) being shorter than or equal to the updating period (c) of the control signal (C) and being synchronized with the control signal (C), said determination period (d) being a period of refreshment of a determination of said flow rate (Q) through said on-off valve (1).

Abstract: A fuel vapor system for a vehicle includes a fuel vapor canister that traps fuel vapor from a fuel tank of the vehicle. A purge valve opens to allow fuel vapor flow to an intake system of an engine and closes to prevent fuel vapor flow to the intake system of the engine. An electrical pump pumps fuel vapor from the fuel vapor canister to the purge valve. A diagnostic module (a) selectively diagnoses a fault in the fuel vapor system based on at least one of: (i) a speed of the electrical pump measured using a pump speed sensor; and (ii) a pressure at a location between the electrical pump and the purge valve, and (b) illuminates a malfunction indicator lamp (MIL) within a passenger cabin of the vehicle when the fault is diagnosed.

Abstract: A system includes a diagnostic module that selectively performs a purge valve leak diagnostic to diagnose a leak in a purge valve in a fuel system of a vehicle. Performing the purge valve leak diagnostic includes determining a level of vacuum in a fuel tank. A control module determines at least one operating condition associated with the vehicle. The at least one operating condition corresponds to an operating condition that affects the level of vacuum in the fuel tank. The control module, based on the at least one operating condition, selectively modifies the purge valve leak diagnostic. Selectively modifying the purge valve leak diagnostic includes at least one of preventing the diagnostic module from performing the purge valve leak diagnostic, preventing the diagnostic module from completing the purge valve leak diagnostic, and causing the diagnostic module to indicate that a result of the purge valve leak diagnostic was indeterminate.

Abstract: Methods and systems are provided for including a single pressure sensor in an evaporative emissions system and fuel system. In one example, a method may include measuring a differential pressure between the evaporative emissions system and the fuel system using a delta pressure sensor coupled across a fuel tank isolation valve disposed between a fuel vapor storage canister of the evaporative emissions system and a fuel tank of the fuel system. Each of the fuel tank isolation valve, the fuel system, and the evaporative emissions system may be checked for degradation using the differential pressure measured by the delta pressure sensor.

Abstract: Methods and systems are provided for estimating an engine exhaust pressure based on outputs from an exhaust oxygen sensor. In one example, a method may include estimating an exhaust pressure of exhaust gas flowing through an engine exhaust passage based on a difference between a first output of an oxygen sensor disposed in the exhaust passage and a second output of the oxygen sensor and then adjusting engine operation based on the estimated exhaust pressure. As one example, both the first and second outputs may be taken while operating the sensor in a variable voltage mode, after increasing a reference voltage of the oxygen sensor from a lower, first voltage to a higher, second voltage.

Abstract: An evaporated fuel processing device has a canister, a vapor passage, a purge passage, a shutoff valve, a storage device and a control device. The canister includes an adsorbent material that adsorbs evaporated fuel generated in a fuel tank. The vapor passage connects the canister and the fuel tank. The purge passage connects the canister and an intake passage of an engine. The shutoff valve is provided in the vapor passage, and adjusts flow rate of gas flowing through the vapor passage. The storage device stores in advance a reference value for the shutoff valve corresponding to internal pressure of the fuel tank. The shutoff valve is controlled based on the reference value, which is obtained from the internal pressure of the fuel tank, and pressure release control is performed on the fuel tank.

Abstract: A computer-implemented platform may comprise hardware and software configured to manage an engine using knock intensity data. Knock intensities from a plurality of combustion cycles may be used to estimate a statistical distribution of knock intensities. The distribution of knock intensities may be used to determine a Descriptive Statistic, which may represent a state of tune of the engine. A calculated Descriptive Statistic may be compared to a desired Descriptive Statistic (e.g., that is representative of operation during a desired tune state of the engine). A deviation between the calculated and desired knock intensity distributions (e.g., between the calculated DS and desired DS) may be used to adjust a control parameter of the engine. Adjustment may be engine-wide. Adjustment may be cylinder-by-cylinder.

Abstract: Methods and systems are provided for adjusting and diagnosing one or more canister purge valves in a fuel vapor recovery system. In one example, a method may include adjusting one or more canister purge valves in a passage coupled to a fuel vapor canister of the fuel vapor recovery system to allow flow between an intake passage and an intake manifold of the engine based on engine operating conditions. Further, the method may include indicating the one or more canister purge valves are degraded and based on a change in air-fuel ratio after adjusting the one or more canister purge valves.

Abstract: A tank ventilation valve has a housing (21), a closing member (4), a sealing seat (5) and a first space (17). A second space (18) is connected to the first space (17) via a control opening (19) that surrounds the sealing seat (5). A spring (6) pretensions the closing member (4) against the sealing seat (5) and closes the control opening (19). The closing member (4) opens as a function of a pressure difference between the first and second spaces (17, 18). The opened closing member (4) opens the control opening (19) so that the first space (17) is connected to a first line (2) connects to fresh air. The second space (18) is connected to a second line (3) that is attachable to a filter. Structure is provided to exert a further negative pressure on the closing member (4) to move the closing member (4) into the open position.

Abstract: A fuel supply system adapted to supply fuel to an internal combustion engine has both a check valve and a purge valve disposed in a purge passage that extends from a canister to connect with an intake passage of the internal combustion engine. A controller estimates a pressure within an intermediate purge passage of the purge passage located between the check valve and the purge valve without relying on the use of a separate pressure detection device to provide information regarding the same.

Abstract: A method, comprising: adjusting an evaporative emissions leak test parameter based on a ratio of cylinder run time of a deactivatable cylinder of an engine, to vehicle run time; and indicating degradation based on the adjusted parameter. The adjusted parameter may thus more accurately reflect the state of a vehicle configured to run with one or more cylinders deactivated. In this way, the evaporative emissions leak test may realize improved robustness and performance metrics, thus reducing warranty costs associated with poor test metrics.

Abstract: Methods are provided for reliving excess vacuum from a fuel tank. In response to elevated fuel tank vacuum levels, a canister purge valve is opened to dissipate the vacuum to an engine intake manifold while the engine is not combusting. Alternatively, the purge valve is opened to dissipate the excess vacuum to the intake manifold while the engine is combusting during conditions when the likelihood of air-fuel ratio errors are lower or when any incurred errors are better tolerated.

Abstract: A portion of a fuel system of a vehicle is disclosed. The vehicle includes a motor-generator-starter connected to an engine. The fuel system includes a fuel tank connected to the engine. The portion of the fuel system includes an evaporative emissions system and an evaporative emissions leak check system connected to the evaporative emissions system. The evaporative emissions leak check system includes a vacuum source. The vacuum source includes the motor-generator-starter connected to the engine. The motor-generator-starter actuates the engine when the vehicle is operated in a non-moving, keyed-off condition for creating a vacuum within an intake manifold of the engine. A method is also disclosed.

Abstract: A vapor solenoid valve is connected so as to lead to a canister. A vapor line connecting port and a purge line connecting port are connected to a vapor line and a purge line, respectively. When switched on and in an open position, the vapor solenoid valve connects a canister connecting port, the vapor line connecting port and the purge connecting port to each other, and thus allows a fuel evaporative gas to flow out of and into a canister or allows air to flow from an air filter. When switched off and in a CLOSED position, the vapor solenoid valve closes the canister connecting port and connects only the vapor line connecting port and the purge line connecting port to each other, and thus inhibits the fuel evaporative gas from flowing out of and into the canister.

Abstract: Systems and methods for internal orifice characterization in an evaporative leak check module are disclosed. In one example approach, a method comprises operating a pump to draw air from an emission control system through an orifice to obtain a reference pressure, and indicating a leak in response to pressure in the emission control system remaining above a threshold pressure while operating the pump to decrease pressure in the emission control system, where the threshold pressure is based on a coded indication and the reference pressure.

Abstract: A combined system for detecting leaks in an evaporative emission control system and for inflating flat tires. The evaporative emission control system includes a vapor capture canister with a purge valve and a system pressure sensor, and the flat tire repair kit includes a reservoir containing tire inflation fluid, an attachment tube for attaching the reservoir to a tire, and a pump selectively connected to the evaporative emission control system and the reservoir. A controller is configured to perform the following actions: initiate a leak detection sequence by pressurizing the evaporative emission control system, and then performing a leak detection operation by measuring the pressure within the evaporative emission control system over time. A tire pressure monitoring system may be provided, allowing the pump to be switched between performing evaporative system testing and inflating a flat tire.

Abstract: A control system according to the principles of the present disclosure includes a fuel system diagnostic module and a pump control module. The fuel system diagnostic module performs a diagnostic test on a fuel system when a vacuum pump is switched off to prevent flow through the vacuum pump and thereby seal a portion of the fuel system from an atmosphere. The vacuum pump includes a cam ring, a rotor that rotates within the cam ring, and vanes that slide into and out of slots in the rotor as the rotor rotates. The pump control module switches on the vacuum pump for a predetermined period to force the vanes out of the slots and into contact with the cam ring to seal the vacuum pump before switching off the vacuum pump for the fuel system diagnostic test.

Abstract: Embodiments for detecting fuel events are presented. In an embodiment, a method comprises performing an action responsive to a fuel event indicated based on output from a hydrocarbon sensor positioned between a fuel tank and a fuel vapor canister. In this way, the hydrocarbon sensor may be used to detect fuel events and engine operation may be adjusted accordingly.

Abstract: A vapor purge system having a tank isolation valve and a canister vent valve, where each valve includes a latching mechanism for maintaining the valves in an open position, and a diagnostic test is performed on the purge system to prove that each of the valves are functioning correctly. Using latching valves in these applications reduces electricity draw from the battery and reduces electrical interference with integrated pressure sensors. The fuel tank is sealed by the tank isolation valve between the fuel tank and a vapor storage canister, and the canister vent valve provides sealing between the canister and the atmosphere, and controls venting of the canister. The diagnostic test is performed using the tank isolation valve and the canister vent valve under different operating conditions.

Abstract: Methods and systems are provided for monitoring a fuel vapor recovery system including a fuel tank isolation valve coupled between a fuel tank and a canister. During selected conditions, the valve is modulated and pressure pulsations in the fuel vapor recovery system are monitored. Valve degradation is identified based on correlations between the valve modulation and the resultant pressure pulsations.

Abstract: A method for detecting pinching of a coupling hose between a tank and a gasoline vapor filter for a vehicle internal combustion engine, with the vapor filter being connected to the engine via a duct including a controllable bleed valve, includes at least one sequence of a step consisting in opening a bleed valve; a step consisting in acquiring a series of measurements of richness of a mixture entering the internal combustion engine over a period greater than a predetermined value, representative of a bleed period of the gasoline vapor filter; and a step consisting in comparing successive measured values and determining if a variation in richness from one measurement to the next remains below a pre-determined threshold for a group of measurements spread over a period greater than a pre-determined value.

Abstract: A method for diagnosing a tank venting valve. This includes measuring a first pressure p1 in the induction pipe of an internal combustion engine; activating the tank venting valve so as to open; measuring a second pressure p2 in the induction pipe of the internal combustion engine after the opening activation of the tank venting valve; calculating a control value K by subtracting the first induction pipe pressure p1 from a second induction pipe pressure p2 and adding a correction pressure pK, which is calculated from the leakage air adaptation of an internal combustion engine; and detecting A defect of the tank venting valve, when the control value K falls below a threshold value.

Abstract: A fuel vapor leak detecting device includes a pump, a housing having a pump passage connected to the pump, a switching valve, a pressure detector, and a control device detecting a shutoff pressure that corresponds to an interior pressure of the pump passage detected by the pressure detector when the pump is actuated while the switching valve is closed. The control device controls the switching valve to be opened at least once and to be closed at least once when the shutoff pressure is out of a specified range. The control device detects a fuel vapor leak when the shutoff pressure is in the specified range.

Abstract: A method for detecting the blockage of a gasoline vapor filter (3) bleed valve (4) for a motor vehicle internal combustion engine (1), includes at least one sequence of the following steps: a step of controlling the opening of the bleed valve (4), a step of measuring at least one operating parameter of the internal combustion engine (1), which is related to the mixture taken into the engine, a step of calculating an indicator, via statistical signal-processing on at least one measured parameter, and of comparing the indicator to a predetermined value. A detection device capable of implementing the method is described.

Abstract: Methods and systems for detecting a refueling event for diagnostics are disclosed. In one example approach a method comprises discontinuing leak diagnostics in response to a temperature change in a fuel vapor canister coupled to a fuel tank in an emission control system while the leak diagnostics are being performed in the emission control system.

Abstract: A tank venting system of an internal combustion engine having an intake manifold, a fuel tank, and an activated carbon filter includes: a tank vent valve; at least one check valve; and a pressure sensor situated between the tank vent valve and the check valve. For diagnosing this tank venting system, a negative pressure which is lower than the ambient pressure outside the engine system is stored between the tank vent valve and the check valve. The stored pressure is changed by controlling the tank vent valve, and the change in the pressure is measured via the pressure sensor. The functioning of the tank venting line, of the check valve, and of the tank vent valve is deduced from the correlation of the opening state of the tank vent valve with the change in pressure.

Abstract: A method of controlling an evaporative emissions system of a vehicle includes determining that a refueling event has been requested by a vehicle occupant, detecting a pressure inside a fuel tank, and impeding opening of a fuel tank inlet if the pressure is above a limit value. After the refueling event, an open/closed status of a fuel inlet access door is monitored, a fuel level inside a fuel tank is monitored, and a vehicle engine an operating condition is monitored. Pressure buildup within the fuel tank is disabled if a) the open/closed status has not changed from closed to open, and b) the fuel level has increased, and c) the vehicle engine is operating. An operator alert may be generated, and/or a fault code may be set in a vehicle diagnostic system.

Abstract: In an internal combustion engine having a turbocharger and a compressor, a discharge point of a tank ventilation system is provided in the intake passage of the internal combustion engine upstream from the turbocharger or the compressor. A Venturi nozzle is situated between the discharge point and a tank venting valve of the tank ventilation system. A defect or a detachment of the line between the Venturi nozzle and the discharge point is detectable with the aid of a change of an adaption value and/or of a correction factor in a control unit of the internal combustion engine or in a computer.