A solenoid assembly includes a solenoid having a coil, a current sensor configured to measure the coil current, and a controller. The controller estimates the coil current using a solenoid model, with output of the solenoid model being an estimated coil current, and receives the measured coil current from the current sensor. The controller also calculates an error value having an error sign by subtracting the estimated coil current from the measured coil current. Responsive to the error value exceeding a calibrated error threshold while the control voltage deviates from a nominal value, the controller diagnoses a solenoid fault condition. Responsive to diagnosing the solenoid fault condition, the controller isolates or identifies a particular solenoid fault condition from among a plurality of possible fault conditions, and records a diagnostic code indicative of the particular solenoid fault condition.

Methods and systems for evaluating whether or not a fuel amount that is greater than a threshold has been release to an engine via fuel injectors when the fuel injectors are commanded off are presented. In one example, an oxygen sensor is activated and engine cranking is prevented until a pumping current of the oxygen sensor is proportionate to a concentration of oxygen sensed via the oxygen sensor so that released fuel may be observed during engine starting.

Various methods and systems are provided for diagnosing a condition of a fuel injector of an engine. In one example, a method for an engine includes injecting a first pulse of fuel as a first pilot injection into a first subset of cylinders of a plurality of engine cylinders, where the first pilot injection precedes a primary injection of fuel into the first subset of cylinders by a duration; correlating a first response in an engine operating parameter to the first pilot injection; and adjusting the primary injection of fuel into the first subset of cylinders based on the first response. In one example, the first pilot injection precedes the primary injection by a predefined short duration and the primary injection of fuel is adjusted within a predefined or preset upper limit and lower limit.

An engine including an exhaust bypass valve and an intake bypass valve. The exhaust bypass valve is disposed in an exhaust bypass channel connecting an outlet of an exhaust manifold and an exhaust outlet of a turbocharger to each other. The intake bypass valve is disposed in an intake bypass channel connecting an inlet of an intake manifold and an inlet of the turbocharger. An intake pressure sensor detects a pressure of the intake manifold. If an instruction value indicating an upper limit or a lower limit of the valve opening degree of the intake bypass valve is continuously output for a predetermined time or more, an engine control device determines that an abnormality occurs in at least one of the exhaust bypass valve and the intake bypass valve.

Methods and systems are provided for using thermoelectric generators to recover waste heat from and diagnose turbocharger systems. In one example, a method may include adjusting one or more engine operating parameters based on an amount of current generated from one or more thermoelectric generators coupled to a turbocharger.

A driving mode setting part sets a driving mode when a vehicle travels by automatic driving. An item setting part sets a prioritized diagnosis. A storage part stores plural diagnosis conditions provided in correspondence to each diagnosis item. A target setting part sets a control target value. A motive power source part controls a motive power source based on the control target value. Each diagnosis item is assigned to the driving mode, for which the diagnosis condition is most easily satisfied. The item setting part sets, as a prioritized item, the diagnosis item assigned to the set driving mode. When the prioritized item is set, the target setting part sets the control target value so that the motive power source attains a state, which is close to the diagnosis condition of the prioritized item.

A number of variations may include a product including an inline diagnostic device connected to a control status line at a position between an electronic control unit (ECU) and a turbocharger component actuator, the inline diagnostic device being constructed and arranged to intercept data being transmitted from the actuator to the ECU, and to process the data intercepted from the actuator to determine whether the components are binding or sticking, and to transmit a signal indicating that the components are binding or sticking.

An engine system is provided with an electronic throttle device to regulate intake amount to the engine, an EGR device (EGR valve) to recirculate a part of exhaust gas of the engine to the engine as EGR gas, and an electronic control unit (ECU) to control the electronic throttle device and the EGR valve based on an operating state of the engine. The ECU performs feedback control of the electronic throttle device such that a detected engine rotation number becomes a target idle rotation number, and sets the target idle rotation number to a predetermined first set value for avoiding engine stall until a predetermined time elapses from start of deceleration and then shifts the target idle rotation number to a second set value lower than the first set value after the predetermined time elapses.

A method for operating a fluid delivery system of a vehicle powerplant is provided. The method includes sampling a fluid pressure in a port injection section of the fluid delivery system, determining if an isolation valve positioned upstream of a direct injection pump is degraded based on the fluid pressure, where the isolation valve separates the port injection section from a direct injection section, and when it is determined that the isolation valve is degraded, indicating said degradation of the isolation valve.

Methods and systems are provided for taking mitigating action where a canister purge valve configured to control an amount of fuel vapors inducted into the engine during purging operations of a fuel vapor storage canister, is indicated as being degraded. In one example, a method comprises controlling an amount of pressure directed to a fuel tank and the fuel vapor storage canister via a pump positioned downstream of the fuel tank and canister to actively route fuel vapors to the canister during a refueling event. In this way, fuel vapors may be prevented from being routed to engine intake under conditions of a degraded canister purge valve, which may reduce opportunity for vehicle stall, improve driveability, and which may reduce release of undesired evaporative emissions to atmosphere.