Methods and systems are provided for enabling a transfer function of a direct injector and a port injector, each fueling an engine cylinder, to be accurately learned. During selected conditions, the direct injected fuel fraction may be actively changed from a target fraction to one of an upper and lower limit of the direct injector so as to provide a measurable air-fuel ratio error. Fueling errors for the distinct fuel injectors is then learned based on the measured air-fuel ratio error relative to the actively changed fuel fraction.

After a system-off state has continued for a preset, time period since a system-off operation, on satisfaction of abnormality diagnosis prerequisites including a condition that a warm-up determination parameter indicating a degree of warm-up of an engine at a system-off time is equal to or greater than a predetermined value, characteristic abnormality diagnosis is performed to determine whether a characteristic abnormality occurs in a fuel pressure sensor. For a time period from a system-on operation to a system-off operation, the warm-up determination parameter is incremented when the engine is in operation, while being decremented after satisfaction of a predetermined condition when the engine is not in operation.

An electronic control unit (ECU) obtains outside air humidity information from a sensor disposed outside a vehicle compartment and inside air humidity information from a sensor inside the vehicle compartment. The ECU includes a humidity information obtainer obtaining the inside air humidity information, a humidity change calculator calculating the inside air humidity information as a difference between (i) a physical quantity correlated with humidity before a start of a dehumidification or a humidification and (ii) a physical quantity correlated with humidity after a switch-off of the dehumidification or the humidification, a soak time calculator calculating, based on the difference of the physical quantities, a soak time from the switch-off of the dehumidification or the humidification to a sensor-diag startable time at which a diagnosis of the outside air humidity sensor is startable, and a comparator comparing the outside air humidity information and the inside air humidity information after a lapse of the soak time from the switch-off of the dehumidification or the humidification.

A method is provided for operating a three step camshaft system during engine position sensor fault conditions. The three step camshaft has multiple cam actuators each having an actuator pin. The method includes: disposing multiple camshaft barrels on a camshaft, each barrel having a slot receiving the actuator pin of a cam actuator during camshaft barrel rotation axially displacing each camshaft barrel to a high lift lobe position, a low lift lobe position and an active fuel management (AFM) lobe position; determining if an engine position sensor is in a fault condition; identifying if the fault condition occurs simultaneously with any of the camshaft barrels positioned in the AFM lobe position; energizing selected cam actuators in communication with the camshaft barrels positioned in the AFM lobe position to axially displace the camshaft barrel away from the AFM lobe position and to the low lift lobe position.

An electronic control unit (ECU) obtains an outside air humidity from an outside air humidity sensor disposed outside a vehicle compartment and an inside air humidity from an inside air humidity sensor disposed inside the vehicle compartment. The ECU includes a humidity obtainer obtaining the inside air humidity and the outside air humidity, and a humidity difference calculator calculating a humidity difference between (i) the inside air humidity after a preset amount of humidity adjustment time from a start of a dehumidification inside the vehicle compartment and (ii) the outside air humidity. The ECU then determines that either the outside air humidity sensor or the inside air humidity sensor is broken when the humidity difference is greater than a first threshold, thereby detecting a failure of the humidity sensor during a travel of a vehicle.

Methods for optimizing exhaust gas system regeneration and cleaning are provided. The exhaust gas system can include an exhaust gas stream supplied by an exhaust gas source to a particulate filter device through an exhaust gas conduit, and a gas sensor having a sampling end disposed within the exhaust gas conduit upstream from the particulate filter device. The methods can include detecting a gas sensor malfunction, detecting particulate filter device soot loading, and performing an optimized maintenance utilizing at least one common technique. A common technique is one which is capable of cleaning a gas sensor and regenerating a PF device. The exhaust gas source can comprise an internal combustion engine and the at least one common technique comprises a post-injection strategy. Systems for performing the disclosed methods are also provided.

A sensor for detecting electrically conductive and/or polarizable particles, in particular for detecting soot particles, includes a substrate, a first electrode layer, and a second electrode layer, which is arranged between the substrate and the first electrode layer. An insulation layer is formed betweem the first electrode layer and the second electrode layer and at least one opening is formed in the first electrode layer and in the insulation layer, wherein the opening of the first electrode layer and the opening of the insulation layer are arranged one over the other at least in some segments in such a way that at least one passage to the second electrode layer is formed.

In order to provide a highly precise and highly responsive humidity detection means with which diagnosis is easy, this control device for an internal combustion engine is characterized in that two or more sensors for detecting the humidity of the atmosphere or a gas mixed with the atmosphere are provided in the middle of the flow in an intake air passage of the internal combustion engine, at least one of these sensors being a relative humidity sensor for detecting the relative humidity, at least one other of the sensors being an absolute humidity sensor for detecting the absolute humidity, and the relative humidity sensor being arranged upstream from the absolute humidity sensor.

An estimation device is applicable to a combustion system in which relative movement of a piston to a cylinder is lubricated with a lubricating oil. An estimation device includes a mixing acquisition unit and a piercing force estimation unit. The mixing acquisition unit acquires a mixing ratio of various components contained in a fuel injected into the combustion chamber. The piercing force estimation unit estimates a piercing force of the fuel injected into the combustion chamber according to the mixing ratio acquired with the mixing acquisition unit to manage reach of the fuel, which is injected into the combustion chamber of the internal combustion engine, at least one of the cylinder and the piston.

Methods and systems are provided for calibrating a vehicle intake humidity sensor positioned in an intake manifold of an engine of the vehicle. In one example, a method is provided, comprising in response to shutdown of the engine, and further responsive to conditions being met for calibrating the intake humidity sensor, requesting a humidity estimate from one or more weather devices, and calibrating the intake humidity sensor based on at least a confidence level in the one or more weather devices. In this way, the intake humidity sensor may be regularly calibrated, under conditions where accurate and robust calibration may be achieved, and where regularly calibrating the intake humidity sensor may improve engine operation and increase fuel economy.