Gm Global Technolgoy Operations, Inc.

Other

Kurt D McLain

Wenbo Wang

Michael A Kropinski

William R Cadman

Layne K Wiggins

Zhong Wang

Robert W Jackson

Lan Wang

Robert J Genslak

Jinchun Peng

Edward Stuteville

Miles K Maxey

David Edward Prout

Kenneth J Kalvelage

Matthew Squire

Elizabeth Sarah Peterson

Jeff DeFrank

A component of a fuel system includes a fuel cap having a head portion connected to a neck portion. The head portion defines: a fluid pressure relief conduit and a relief valve passage that extends into and through the head portion that terminates at a valve head opening formed by an inner surface of the head portion. The inner surface of the head portion and the inner surface of the neck portion cooperate to form a fuel cap cavity. The fluid cap cavity is fluidly-connected to the fluid pressure relief conduit by way of the valve head opening formed by the inner surface of the head portion. A relief valve is movably arranged within the relief valve passage for permitting selective fluid communication of the fuel cap cavity with the fluid pressure relief conduit. A locking apparatus is arranged within the fuel cap cavity.

Component of a fuel system, fuel system and method for operating the same

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.

Apparatus and method of determining a leak condition of a fuel system

A portion of a fuel system of a vehicle is disclosed. The vehicle includes a brake system. The fuel system includes a fuel tank connected to an engine. The portion of the fuel system includes an evaporative emissions system and an evaporative emissions leak check system selectively fluidly-connected to the evaporative emissions system. The evaporative emissions leak check system includes a vacuum source. The vacuum source includes a vacuum pump connected to a brake boost device that provides power braking to the brake system of the vehicle. A method is also disclosed.

A control system includes a switching valve control module, a pressure determination module, and a fuel system diagnostic module. The switching valve control module actuates a switching valve in a fuel system of a vehicle between a first position and a second position, the first position venting a suction side of a vacuum pump in the fuel system to an atmosphere, the second position sealing the suction side of the vacuum pump from the atmosphere. The pressure determination module determines a first pressure on the suction side of the vacuum pump when the switching valve is in the first position, and determines a second pressure on the suction side of the vacuum pump when the switching valve is in the second position. The fuel system diagnostic module selectively diagnoses a fault in the vacuum pump based on the first pressure and the second pressure.

System and method for diagnosing faults in vacuum pumps of fuel systems and for diagnosing leaks in fuel systems

A vehicle includes an engine, a sealed fuel system having a fuel tank, a canister for storing fuel vapor, a vapor circuit external to the fuel tank, and a control valve. The vapor circuit includes an absolute pressure sensor and a switching valve connecting the fuel tank to the control valve. A controller evaluates or diagnoses a vapor purge function of the sealed fuel system using vacuum measurements from the absolute pressure sensor, executing or diagnosing only when the engine is running, purge is enabled, and the pump is off. The controller diagnoses the vapor purge function by comparing the vacuum measurements to a threshold vacuum. An apparatus includes the vapor circuit and controller. A method for diagnosing the vapor purge function includes actuating the switching valve, measuring a vacuum in the system using the absolute pressure sensor, and comparing the measured vacuum to a threshold vacuum.

Low purge flow vehicle diagnostic tool

A method of determining an engine intake air leak may include measuring an air flow rate into an internal combustion engine, comparing the measured air flow rate to a first predetermined air flow limit, calculating an estimated air flow rate into the engine when the measured air flow rate is less than the first predetermined air flow limit, comparing the estimated air flow rate to second and third predetermined air flow limits, and indicating an air leak when the estimated air flow rate is greater than the second predetermined air flow limit and less than the third predetermined air flow limit.

Detection of engine intake manifold air-leaks

An engine control system comprises a signal deviation module, a variation determination module, and a sensor diagnostic module. The signal deviation module receives a signal from a sensor monitoring an operating condition of an engine and determines a plurality of signal deviations. Each of the plurality of signal deviations is based on a magnitude of a difference between the signal at a first time and the signal at a second time. The second time is different than the first time. The variation determination module generates a variation value based on the plurality of signal deviations during a period. The sensor diagnostic module determines a state of the sensor based on the variation value.

Intermittent sensor detection using signal string length

A control system for an engine having a catalytic converter includes an energy calculation module that calculates a calculated mass air flow (MAF) of intake air of the engine based on a requested torque and a requested spark timing that correspond to a desired thermal energy of exhaust of the engine, and that determines an expected thermal energy of the exhaust based on the calculated MAF, and an energy residual module that determines a thermal energy residual of the exhaust based on the expected thermal energy and an estimated thermal energy of the exhaust, wherein the estimated thermal energy is based on a measured MAF of the intake air. The control system includes an energy evaluation module that determines a diagnostic result that indicates whether the catalytic converter is operating within a target temperature range based on the thermal energy residual. Related control methods are also provided.

Torque model-based cold start diagnostic systems and methods

A method of determining whether a fault condition of an intake air temperature (IAT) sensor of an engine is present includes estimating a first manifold absolute pressure (MAP) based on a previously estimated first MAP and an estimated first mass air flow (MAF) as a function of the previously estimated first MAP and estimating a second MAP based on a previously estimated second MAP and a currently measured MAF. An IAT difference is determined based on the first MAP and the second MAP. Whether the fault condition of the IAT sensor is present is determined based on the IAT difference.

Intake air temperature rationality diagnostic

A restriction diagnostic system for a vehicle comprises a pressure difference module and a diagnostic module. The pressure difference module determines a pressure difference between an ambient air pressure and a filtered air pressure measured at a location between an air filter and a valve that is selectively opened to enable ambient airflow through the air filter to a fuel vapor canister. The diagnostic module selectively diagnoses restriction of the airflow through the air filter when the pressure difference is greater than a predetermined pressure.

Restricted filter diagnostic system and method

A method of evaluating intake air temperature (IAT) sensor rationality may include measuring a first intake air temperature associated with an engine using an IAT sensor when the engine is in a non-operating condition, determining a second intake air temperature associated with the engine using a hot wire air flow meter when the engine is in the non-operating condition, and indicating an IAT sensor fault when a difference between the first and second intake air temperatures exceeds a predetermined temperature limit.

Intake air temperature diagnostic system

A control system comprising a wind condition determination module that determines a wind condition and a leak detection test control module that selectively diagnoses a vapor leak associated with a vehicle based on the wind condition. A method comprising determining a wind condition and selectively diagnosing a vapor leak associated with a vehicle based on the wind condition.

Wind condition based vapor leak detection test

A system includes a control module, a valve control module, and a diagnostic module. The control module controls a valve of a variable intake manifold when the system operates in a first mode. The control module commands the valve to a first position when a desired airflow through the variable intake manifold is greater than a threshold and commands the valve to a second position when the desired airflow is less than the threshold. The valve control module controls the valve when the system operates in a second mode. The valve control module commands the valve to move from the second position to the first position when the desired airflow is less than the threshold. The diagnostic module determines an operating state of the valve based on whether the valve is detected at the first position a predetermined period after the valve control module commands the valve.

Variable intake manifold diagnostic systems and methods

A diagnostic system for an internal combustion engine includes an intake air temperature (IAT) determination module, a reference temperature determination module, and an adaptive learning module. The IAT determination modules determines a first IAT using an IAT sensor at a first time and determines a second IAT using the IAT sensor at a second time. The reference temperature determination module determines a first frequency based on a first voltage output of a MAF sensor at the first time and determines a second frequency based on a second voltage output of the MAF sensor at the second time. The adaptive learning module determines a temperature-frequency relationship based on the first IAT, the second IAT, the first frequency and the second frequency.

Intake air temperature sensor diagnostic systems with adaptive learning modules

A method of diagnosing a malfunction of a tuning valve of an intake manifold coupled to an internal combustion engine is provided. The method includes: commanding the tuning valve to at least one of a closed and an opened position; computing an average deviation of manifold absolute pressure; determining an average deviation threshold using fuzzy logic based on engine speed and airflow per cylinder; comparing the average deviation to the average deviation threshold; and diagnosing a malfunction of the tuning valve based on a comparison of the average deviation and the average deviation threshold.

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Clarkston, MI, United States of America

Kurt D McLain