Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, entry conditions for entering a driveline sailing mode are described. Driveline sailing mode may improve driveline torque response and vehicle drivability.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, driveline operating modes may be manually selected to improve hybrid driveline operation during off road conditions. The approaches may improve vehicle drivability and reduce driveline degradation.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, an engine may be started in one of two ways depending on operating conditions. In particular, the engine may be started via a lower power output electric machine or a higher power output electric machine.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, an engine is accelerated to a speed of a driveline integrated starter/generator before the engine is coupled to the driveline integrated starter/generator.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, torque demand of a driveline after a shift is forecast to determine if it is desirable to start the engine early so that engine torque is available after the shift. The approach may improve vehicle torque response.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, a driveline disconnect clutch transfer function may be adapted in response to engine operating conditions during closing of the driveline disconnect clutch.

Abstract: A method for adjusting an air-fuel ratio of an engine is disclosed. In one example, the engine air-fuel ratio is adjusted in response to a duty cycle and frequency of a post catalyst oxygen sensor. The method may improve catalyst efficiency.

Abstract: A method for adjusting an air-fuel ratio of an engine is disclosed. In one example, the engine air-fuel ratio is adjusted in response to a duty cycle and frequency of a post catalyst oxygen sensor. The method may improve catalyst efficiency.

Abstract: A method for adjusting an air-fuel ratio of an engine is disclosed. In one example, the engine air-fuel ratio is adjusted in response to a duty cycle and frequency of a post catalyst oxygen sensor. The method may improve catalyst efficiency.

Abstract: A method for adjusting an air-fuel ratio of an engine is disclosed. In one example, the engine air-fuel ratio is adjusted in response to a duty cycle and frequency of a post catalyst oxygen sensor. The method may improve catalyst efficiency.

Abstract: A system for a vehicle including an internal combustion engine configured to provide the exclusive source of motive power to the vehicle, an energy storage device coupled to an electrical system, and a charging interface coupled to the energy storage device, the charging interface configured to attach to an external charging device.

Abstract: An engine air/fuel ratio control system maintains average engine air/fuel ratio at a desired lean air/fuel ratio during cold engine operation in order to more rapidly warm the catalytic converter. Fuel delivered to the engine is modulated with a truncated triangular wave which is truncated to minimize lean air/fuel excursions. An error signal is generated from the exhaust gas oxygen sensor output, and a proportional plus integral control responsive to the error signal generates a feedback correction value to maintain the desired air/fuel ratio. Gain of the controller is increased when the error signal indicates engine air/fuel operation leaner than a preselected air/fuel ratio to further minimize excursions in a fuel enleanment direction.

Abstract: An engine air/fuel control system is disclosed which is responsive to first and second exhaust gas oxygen sensors respectively positioned upstream and downstream of a catalytic converter. Air/fuel feedback control is disabled, and a rich offset to fuel flow is provided to cause a corresponding rich offset in engine air/fuel ratio. A predetermined time afterwards, a lean offset in fuel flow is provided. Air/fuel feedback control is reinitiated, and fuel delivery is biased with a rich fuel bias when the downstream sensor indicates excessively lean engine exhaust in response to the lean fuel offset and biased with a lean fuel bias when the downstream sensor indicates excessively rich exhaust gases in response to the rich fuel offset.