A controller for an internal combustion engine includes: a failure determination section which determines a failure state in a case where a relative rotation phase of an intake side valve opening and closing timing control mechanism does not change when controlling the mechanism after starting the driving of a starter motor and trying to change the relative rotation phase of the mechanism in a start control for starting an internal combustion engine. When the section determines a failure, the controller performs at least one of an intake air amount increase control in which an opening degree of a throttle valve is increased, an ignition timing advance angle control in which injection of fuel is performed at a timing earlier than a set timing and ignition is performed, and a multi-injection control in which the fuel is injected immediately before the ignition in addition to the fuel injection in an intake stroke.

An electronic control unit of a control device for an internal combustion engine executes, for a first cycle, first drive processing for controlling an actuator such that a pin drive operation is executed for switching from a first cam to a second cam, executes second drive processing for controlling the actuator such that the pin drive operation is executed again for a second cycle, and executes abnormality determination processing for determining that a cam switching mechanism has an abnormality in a case where a pin returns to a reference position by using a pin return section following a cam switching section of the first cycle after the execution of the first drive processing and the pin returns to the reference position by using the pin return section following the cam switching section of the second cycle after the execution of-the second drive processing.

A method of controlling a continuously variable valve timing system, may include determining whether there is an error of a position of a cam, performing a passive control based on a value learned about a position of the cam during previous driving when it is determined that there is an error of the position of the cam, determining whether a motion of the continuously variable valve timing system is stopped while the passive control is performed based on the value learned about the position of the cam during the previous driving, learning the stopping position of the continuously variable valve timing system when it is determined that the motion of the continuously variable valve timing system is stopped, and learning a position for limp-home of the continuously variable valve timing system and then controlling the continuously variable valve timing system to the learned position for the limp-home.

An engine includes a plurality of combustion cylinders configured to burn a fuel to power the engine, and a plurality of fuel injectors. Each of the fuel injectors is arranged to distribute fuel delivered from a fuel tank to one of the plurality of combustion cylinders. The engine also includes a controller programmed to adjust a fuel trim signal gain based on sensing exhaust flow downstream of the combustion cylinders. The controller is also programmed to monitor a cumulative misfire count for each of the plurality of combustion cylinders. The controller is further programmed to issue a prognosis message identifying a state of health of at least one of the plurality of fuel injectors in response to a fuel trim signal gain exceeding an adjustment threshold and a cumulative misfire count greater than a misfire threshold.

A method for detecting a sticking tank vent valve in a motor vehicle, a temperature sensor being situated in a tank vent line between the tank vent valve and an inlet point into an intake manifold or into a turbocharger and sticking of the tank vent valve being detected when the absolute value of a correlation of a calculated tank ventilation mass flow and of a signal value of the temperature sensor violates a predefinable threshold value.

Methods and systems are provided for diagnosing compressor bypass valve degradation. In one example, a method may include indicating degradation of a compressor bypass valve coupled in a compressor bypass based on intake aircharge temperature measured upstream of a compressor inlet via an air charge temperature sensor.

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.

Systems and methods for determining operation of a cylinder deactivating/reactivating device are disclosed. In one example, degradation of the cylinder deactivating/reactivating device is based on intake manifold oxygen concentration.

Methods and systems are provided for mitigating the effects of a leaky fuel injector during vehicle idle stop conditions. In one example, a method may include identifying the cylinder with a leaky fuel injector, and at or during engine shutdown, positioning the engine to a selected position based on the identified cylinder such that an exhaust valve of the identified cylinder is at least partly open.

Methods and systems are provided for a vehicle wirelessly communicating with a central server. In one example, a method may include monitoring faults and sending engine conditions along with driver inputs to the central server for processing.