Abstract: A stop/start system and method for an engine of a vehicle include a valve control system configured for full lift control of respective intake and exhaust valves of a plurality of cylinders of the engine and a controller of the engine configured to perform an engine stop event including initiating a fuel shutoff (FSO) event whereby fueling to the engine is disabled and the engine fully stops after a stop period and, in response to initiating the FSO event, commanding the valve control system to close each intake valve prior to closing its respective exhaust valve to (i) expel any residual gases from the cylinders during respective exhaust strokes prior to closing the respective exhaust valves, and (ii) prevent air-only intake and compression within the cylinders during the stop period to thereby mitigate or eliminate noise/vibration/harshness (NVH) caused by the air-only intake and compression.

Abstract: An emissions control system for a vehicle having an exhaust system with an exhaust gas conduit and a catalytic converter configured to receive exhaust gas from an engine is provided. In one example implementation, the system includes an engine controller configured to control the engine to adjust an air to fuel ratio (lambda) thereof. The engine controller is configured to operate the engine with at least one of the following lambda control strategies (i) a first control strategy comprising operating at a first reference lambda modified by a first percent kick, and a first rich lambda lag time shorter than a first lean lambda lag time, and (ii) a second control strategy comprising operating at a second reference lambda modified by a second percent kick, and a second rich lag time longer than a second lean lambda lag time, to thereby simultaneously meet predetermined NOx and CO emissions targets.

Abstract: An emissions control system for a vehicle having an exhaust system with an exhaust gas conduit and a catalytic converter configured to receive exhaust gas from an engine is provided. In one example implementation, the system includes an engine controller configured to control the engine to adjust an air to fuel ratio (lambda) thereof. The engine controller is configured to operate the engine with at least one of the following lambda control strategies (i) a first control strategy comprising operating at a first reference lambda modified by a first percent kick, and a first rich lambda lag time shorter than a first lean lambda lag time, and (ii) a second control strategy comprising operating at a second reference lambda modified by a second percent kick, and a second rich lag time longer than a second lean lambda lag time, to thereby simultaneously meet predetermined NOx and CO emissions targets.

Abstract: A control system and method for a vehicle having a powertrain comprising a torque generating system and an automatic transmission each utilize a pedal position sensor configured to measure a position of an accelerator pedal of the vehicle and a controller configured to, based on the accelerator pedal position, detect a pedal tip-in or tip-out event and, in response to detecting the pedal tip-in or tip-out event: (i) determine a desired output torque for the torque generating system corresponding to the pedal tip-in or tip-out event and (ii) command the torque generating system to gradually transition, over a period, from its current output torque to the desired output torque to mitigate clunk caused by abrupt contact between gear teeth of the torque generating system shaft and the automatic transmission shaft.

Abstract: A control system and method for a vehicle having a powertrain comprising a torque generating system and an automatic transmission each utilize a pedal position sensor configured to measure a position of an accelerator pedal of the vehicle and a controller configured to, based on the accelerator pedal position, detect a pedal tip-in or tip-out event and, in response to detecting the pedal tip-in or tip-out event: (i) determine a desired output torque for the torque generating system corresponding to the pedal tip-in or tip-out event and (ii) command the torque generating system to gradually transition, over a period, from its current output torque to the desired output torque to mitigate clunk caused by abrupt contact between gear teeth of the torque generating system shaft and the automatic transmission shaft.

Abstract: A vehicle powertrain control technique includes obtaining, by a controller, a set of parameters each indicative of a gear shift operation for an automatic transmission. Cased on the set of parameters, the controller detects whether a gear shift operation of the automatic transmission is imminent. In response to detecting that the gear shift operation of the automatic transmission is imminent, the controller (i) determines a desired reduction in powertrain output torque for performing the gear shift operation and (ii) controls the powertrain to temporarily reduce its torque output via a technique other than spark retardation. After reducing the powertrain output torque, the controller commands the automatic transmission to perform the gear shift operation. The temporary powertrain output torque reduction is achieved by controlling a variable valve control (VVC) system of an engine, such as commanding a lower valve lift profile, or decreasing power supplied to an electric motor.