Abstract: A vehicle includes a powerplant, such as an engine, configured to power front and rear wheels, and a controller. The controller is programmed to, brake a first of the front wheels and a first of the rear wheels while powering a second of the front wheels and a second of the rear wheels to warm those tires, and subsequently brake the second front wheel and the second rear wheel while powering the first front wheel and the first rear wheel to warm those tires.

Abstract: Systems and methods for estimating a temperature of an after treatment device in an exhaust system of an engine are described. In one example, the temperature is estimated during condition when an engine exits a fuel cut-out mode and excess fuel is delivered to the after treatment device for the purpose of increasing after treatment device efficiency.

Abstract: Systems and methods for estimating a temperature of an after treatment device in an exhaust system of an engine are described. In one example, the temperature is estimated during condition when an engine is in a fuel cut-out mode and fuel vapors are being released to the engine via a fuel vapor storage canister.

Abstract: Systems and methods for estimating a temperature of an after treatment device in an exhaust system of an engine are described. In one example, the temperature is estimated during condition when an engine exits a fuel cut-out mode and excess fuel is delivered to the after treatment device for the purpose of increasing after treatment device efficiency.

Abstract: Systems and methods for estimating a temperature of an after treatment device in an exhaust system of an engine are described. In one example, the temperature is estimated during condition when an engine is in a fuel cut-out mode and fuel vapors are being released to the engine via a fuel vapor storage canister.

Abstract: Methods and systems are provided for injector correction learned while a direct injector delivers fuel as a group of fuel injections per cylinder event. The correction is learned using a pressure based injector balancing approach while relies on a sensed pressure drop across the group of fuel injections. Errors for individual pulses of the group of injections is learned as a function of inter-injection spacing and individual pulse-width commands.

Abstract: A vehicle includes a powerplant, such as an engine, configured to power front and rear wheels, and a controller. The controller is programmed to, brake a first of the front wheels and a first of the rear wheels while powering a second of the front wheels and a second of the rear wheels to warm those tires, and subsequently brake the second front wheel and the second rear wheel while powering the first front wheel and the first rear wheel to warm those tires.

Abstract: 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.

Abstract: Methods and systems are provided for injector correction learned while a direct injector delivers fuel as a group of fuel injections per cylinder event. The correction is learned using a pressure based injector balancing approach while relies on a sensed pressure drop across the group of fuel injections. Errors for individual pulses of the group of injections is learned as a function of inter-injection spacing and individual pulse-width commands.

Abstract: A vehicle includes a powerplant, such as an engine, configured to power front and rear wheels, and a controller. The controller is programmed to, brake a first of the front wheels and a first of the rear wheels while powering a second of the front wheels and a second of the rear wheels to warm those tires, and subsequently brake the second front wheel and the second rear wheel while powering the first front wheel and the first rear wheel to warm those tires.

Abstract: Methods and systems are provided for temperature control of a high pressure pump (HPP) of a direct injection system. When direct injection is disabled, the HPP and the associated direct injectors are intermittently operated when the HPP temperature rises above a modeled threshold temperature. The HPP and injectors are operated until the HPP temperature falls below the modeled threshold temperature.

Abstract: Methods and systems are provided for learning a cylinder-to-cylinder air variation. During conditions when a PFDI engine is operated in a port-injection only mode, prior to port fuel injection, a direct-injection fuel rail pressure may be lowered via direct-injection. Then, prior to a spark event in a port-injected cylinder, the direct-injector may be transiently opened to use the rail pressure sensor for estimating a cylinder compression pressure, and inferring cylinder air charge therefrom.

Abstract: Methods and systems for simultaneously operating port fuel injectors and direct fuel injectors of an internal combustion engine are described. In one example, port fuel injection timing is adjusted to reduce particulate matter formation in the engine so that particulate filter loading may be reduced until a time when the particulate filter may be purged.

Abstract: Methods and systems for simultaneously operating port fuel injectors and direct fuel injectors of an internal combustion engine are described. In one example, operation of a port fuel injector is deactivated in response to an indication of reduced performance of a direct fuel injector so that degradation of the direct fuel injector may be reduced.

Abstract: Methods and systems are provided for reducing port injection fuel errors by selectively reactivating a direct fuel injector. Responsive to an increase in driver demand received while delivering fuel to a cylinder via port injection only, wherein the increase in driver demand is received late in the port injection window, the port injection error is addressed by reactivating a direct injector on the same engine cycle and delivering at least a portion of the fuel mass corresponding to the error via the direct injector. Additionally, a portion of the fuel mass may be delivered by the port injector on the same engine cycle by extending the end of injection timing, if possible.

Abstract: Methods and systems are provided for reducing direct injector fueling errors due to injection variability in a transition region of a direct injector map. Fuel injection, including usage of one or more direct and port injected fuel pulses, may be planned based on engine operating conditions including engine temperature and driver demand. Responsive to any of the direct injected fuel pulses having a pulse-width that lies in a high variability transition region of the direct injector, the fuel injection may be adjusted via adjustments to a number and/or split ratio of the injections so as to not operate in the transition region.

Abstract: Methods and systems for simultaneously operating port fuel injectors and direct fuel injectors of an internal combustion engine are described. In one example, a duration of a port fuel injection window is increased to improve engine performance and a direct fuel injector fuel pulse width is dynamically adjusted to improve accuracy of an amount of fuel delivered during a cylinder cycle.

Abstract: A vehicle includes a powerplant, such as an engine, configured to power front and rear wheels, and a controller. The controller is programmed to, brake a first of the front wheels and a first of the rear wheels while powering a second of the front wheels and a second of the rear wheels to warm those tires, and subsequently brake the second front wheel and the second rear wheel while powering the first front wheel and the first rear wheel to warm those tires.

Abstract: 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.

Abstract: Methods and systems for simultaneously operating port fuel injectors and direct fuel injectors of an internal combustion engine are described. In one example, a port fuel injection window is shorted to provide time for scheduling a direct fuel injector pulse width so that the direct fuel injector pulse width may be adjusted so that a desired amount of fuel enters a cylinder.