A torque request module determines a torque request for an engine based on a driver input. A cylinder control module determines a target fraction of a total number of cylinders of the engine to be activated based on the torque request. An air fuel imbalance (AFIM) module selectively commands that the cylinder control module set the target fraction based on a predetermined fraction of the total number of cylinders of the engine to be activated. The cylinder control module further: sets the target fraction based on the predetermined fraction in response to the command; and activates and deactivates opening of intake and exhaust valves of the cylinders of the engine based on the target fraction. The AFIM module further, while the target firing fraction is set based on the predetermined fraction, selectively diagnoses the presence of an AFIM fault based on samples of a signal from an oxygen sensor.

A method for detecting leakage of a high pressure fuel pump of a vehicle includes: turning off starting of an engine; after the starting of the engine is turned off, determining whether restarting of the engine occurs by a fuel rail pressure condition in which internal fuel pressure of a fuel rail connected between the high pressure fuel pump and an injector of the engine is less than or equal to a reference pressure; when the restarting of the engine occurs by the fuel rail pressure condition, determining whether a reference pressure reach time of the internal fuel pressure of the fuel rail is less than or equal to a reference time; and when the reference pressure reach time of the internal fuel pressure of the fuel rail is less than or equal to the reference time, storing a number of times of restarting of the engine.

An electronic switching module for connecting first and second throttle assemblies to an electronic control module of a vehicle that controls an engine of the vehicle includes first throttle assembly ports adapted to receive first throttle primary sensor position data and first throttle secondary sensor position data and second throttle assembly ports adapted to receive second throttle primary sensor position data and second throttle secondary sensor position data. A controller is connected to the first and second throttle assembly ports and an electronic control module port and is adapted to receive and compare the first throttle primary sensor position data and the first throttle secondary sensor position data and send an engine idle signal to the electronic control module via the electronic control module port when the comparison does not show a first predetermined relationship. The controller is also adapted to receive and compare the second throttle primary sensor position data and the second throttle secondary sensor position data and send an engine idle signal to the electronic control module via the electronic control module port when the comparison does not show a second predetermined relationship.

Methods and systems are provided for a particulate matter sensor. In one example, the sensor may include a concave inlet for admitting exhaust gas from an exhaust passage downstream of a particulate filter into the sensor.

Methods and systems are provided for a diagnostic of a pressure sensor. In one example, a method includes bypassing one or more vapor canisters and determining a condition of the pressure sensor based on feedback from a hydrocarbon sensor.

An on-board vehicle computer system is configured to detect a condition of a vehicle; identify a de-rate cause for the vehicle in a hierarchical set of de-rate causes, wherein the de-rate cause is associated with the condition; select a de-rate type from a set of possible de-rate types based at least in part on the de-rate cause; select an initial de-rate level from a set of possible de-rate levels based at least in part on the de-rate cause; present an operator notification associated with the de-rate cause via an operator interface; activate a de-rate for the vehicle according to the de-rate type and the initial de-rate level; detect a change in the vehicle condition; and update the initial de-rate level based at least in part on the change in the vehicle condition.

A diagnostic system for a vehicle includes a difference module, a Fourier module, and a fault module. The difference module determines pressure differences for a camshaft revolution based on differences between: first pressures within first chambers of a camshaft phaser measured during the camshaft revolution, wherein the first pressures within the first chamber control advancement of the camshaft relative to a crankshaft of an engine; and second pressures within second chambers of the camshaft phaser measured during the camshaft revolution, wherein the second pressures within the second chamber control retardation of the camshaft relative to the crankshaft of the engine. The Fourier module performs a Fourier Transform (FT) based on the pressure differences to produce FT data. The fault module, based on the FT data, selectively indicates that a fault is present in a variable valve lift mechanism that is actuated by the camshaft.

Methods and systems are provided for diagnosis of oil dilution in an engine. In one example, a method may include sealing a crankcase and spinning an engine unfueled to heat and vaporize the oil in response to detection of rich engine operation. Pressure measurements at the sealed crankcase may be collected and compared to a baseline to diagnose a presence of fuel in the oil.

A heating system includes at least one electric heater disposed within the fluid flow system. A control device includes a microprocessor and is configured to determine a temperature of the at least one electric heater based on a model and at least one input from the fluid flow system. The control device is configured to provide power to the at least one electric heater based on the temperature of the at least one electric heater.

A device for measuring temperature of a turbine wheel in a turbocharger includes: a guide that passes infrared ray generated from the turbine wheel and includes a coolant path; a protection unit that protects an optical head which senses the infrared ray; and a signal processing unit that measures a temperature of the turbine wheel by processing a signal corresponding to the sensed infrared ray.