A valve opening and closing timing control apparatus includes a valve opening and closing timing control apparatus provided at a camshaft for an intake valve of an internal combustion engine and a valve opening and closing timing control apparatus provided at a camshaft for an exhaust valve and includes a control unit changing a phase of one of the valve opening and closing timing control apparatus for the intake valve and the valve opening and closing timing control apparatus for the exhaust valve serving as an electric type which malfunctions to a most advanced angle phase and changing a phase of the other of the valve opening and closing timing control apparatus which is inhibited from malfunctioning to an advanced angle side in a case where one of the valve opening and closing timing control apparatus serving as the electric type malfunctions.

A drive current applied to a coil is reduced from a time at which a first collision signal indicating collision of a movable core with a valve element is input to a time at which a second collision signal indicating collision of the movable core with a stationary core is input.

Methods and systems are provided for determining whether an exhaust gas recirculation (EGR) valve is degraded and being held open in a vehicle system. In one example, a method may include, in response to an engine pull-down request, closing a throttle coupled to an intake manifold of the engine, closing the EGR valve, propelling the vehicle via an electric motor, and checking operation of the EGR valve based on both intake manifold pressure and exhaust pressure. For example, if the intake manifold pressure does not decrease by a threshold amount relative to the exhaust pressure, EGR valve degradation may be indicated.

Methods and systems are provided for diagnostics of a cylinder valve actuation mechanism in a variable displacement engine (VDE). In one example, during an engine-off condition, the engine may be rotated unfueled, via a starter motor, and a reference exhaust air flow may be estimated. One or more deactivatable engine cylinders may then be deactivated and degradation of the cylinder valve actuation mechanism may be indicated based on a difference between the exhaust air flow following the cylinder deactivation and the reference exhaust air flow.

A throttle valve abnormality determination device includes a permission/rejection determination unit configured to determine whether or not to permit a sticking determination of a throttle valve. The determination unit is configured to prohibit the sticking determination if a first temperature, which is a temperature in a passage through which intake air flows, is less than or equal to a freezing temperature at which the throttle valve may be frozen when an engine is started and, after prohibiting the sticking determination, permit the sticking determination if an integrated value of a heat amount conversion value based on a second temperature, which is a temperature in the passage, and an intake air amount exceeds a threshold value when the second temperature is greater than or equal to a de-freezing temperature at which a frozen portion of the throttle valve is de-frozen.

Systems and methods for operating an engine in response to a condition of an engine air intake throttle being degraded are presented. In one example, the engine air intake throttle is held closed while a position of a fuel vapor storage canister vent valve is adjusted to control air flow into the engine based on a position of an accelerator pedal. In this way, the engine air amount may be adjusted to provide additional torque from an engine while a throttle is degraded.

A method for mitigating an electrical actuator fault in a system containing multiple actuators includes: applying multiple predetermined conditions to each of multiple actuators in a vehicle system to identify when at least one of the multiple actuators is in a faulted condition; and increasing an input voltage to all of the actuators to increase an output of the at least one of the multiple actuators in the faulted condition to mitigate the faulted condition.

A method for analyzing a fuel injection system includes generating injection commands, including attenuating a predetermined fuel request schedule for a different one of the plurality of injectors in a plurality of test cycles. Fuel is injected according to the injection commands to complete the plurality of test cycles. The processor generates pump commands for the pump to maintain a substantially constant pressure of the common rail during the test cycles. First command data are stored for the plurality of test cycles corresponding to the injection commands sent during the test cycles. Second command data are stored for the test cycles corresponding to the pump commands sent during the test cycles. The processor processes the first command data and the second command data to determine flow characteristics of the plurality of fuel injectors.

A method and apparatus is disclosed for testing a fuel injector of an internal combustion engine equipped with a plurality of fuel injectors to detect injector clogging. A test injector is switched off. A requested value of a fuel quantity to be injected by the other fuel injectors of the plurality of fuel injectors is adjusted to operate the internal combustion engine in idle mode. A value of an oxygen concentration in an exhaust gas is measured. A value of a fuel quantity that has been injected is estimated as a function of the measured value of the oxygen concentration. A fuel quantity drift of each fuel injector is calculated as a function of the requested values and the estimated values of the fuel quantity provided by the injector tests. Each fuel quantity drift is used to identify if the corresponding fuel injector is clogged.

A method for operating an internal combustion engine with multiple cylinders. Each cylinder of the internal combustion engine includes at least one fuel injector, and each fuel injector is activated for opening and closing via a solenoid valve of the respective fuel injector. Structure-borne sound waves emitted by the fuel injectors and/or accelerations caused by the fuel injectors are detected by measurement. The structure-borne sound waves detected by measurement and/or the accelerations detected by measurement are evaluated, and based on the evaluation, characteristics of the fuel injectors are automatically determined.