Abstract: Controllers and methods for managing transitions into and/or out of a cylinder cut off mode are described. In some embodiments, a skip fire based transition into a cylinder cut off mode is used in which the fraction of working cycles that are fired is gradually reduced to a threshold firing fraction. Once the threshold firing fraction has been reached, all of the working chambers are deactivated.

Abstract: Controllers and methods for managing transitions into and/or out of a cylinder cut off mode are described. In some embodiments, a skip fire based transition into a cylinder cut off mode is used in which the fraction of working cycles that are fired is gradually reduced to a threshold firing fraction. Once the threshold firing fraction has been reached, all of the working chambers are deactivated.

Abstract: Methods and controllers are described that facilitate the determination of an operational skip fire firing fraction for an engine based at least in part noise levels and/or vehicle vibration levels that are not induced by engine operation. In some embodiments, the firing fraction is determined based at least in part of noise or vibrations associated with road roughness and/or cabin noise levels.

Abstract: A system and method for dynamically varying an amount slippage of a Torque Converter Clutch (TCC) provided between an engine and a transmission of a vehicle in response to non-powertrain factors. By varying a slippage output signal, the amount of TCC slippage between the engine and the transmission can be adjusted. Small amounts of slippage, relative to large amounts of slippage, provide (a) improved vehicle fuel economy, but (b) induce more powertrain noise and vibration in the vehicle cabin. By dynamically adjusting the slippage, a tradeoff between improved fuel economy vs. a satisfying driver experience can be realized.

Abstract: Methods and arrangements are described for controlling transitions between firing fractions during skip fire operation of an engine in order to help smooth the transitions. Generally, firing fractions transitions are implemented gradually, preferably in a manner that relatively closely tracks manifold filling dynamics. In some embodiments, the commanded firing fraction is altered each firing opportunity. Another approach contemplates altering the commanded firing fraction by substantially the same amount each firing opportunity for at least a portion of the transition. These approaches work particularly well when the commanded firing fraction is provided to a skip fire controller that includes an accumulator functionality that tracks the portion of a firing that has been requested, but not delivered, or vice versa.

Abstract: A gasoline compression ignition engine is operated in two modes. In a one mode of operation the engine is operated with a firing fraction of one, corresponding to all of the cylinders being active, working cylinders. In a second skip fire mode of operation a firing fraction of less than one may be used under conditions, such as a low load condition, to improve efficiency. The skip fire mode of operation may also be selected in part based on other considerations, such as maintaining an exhaust temperature conducive for efficient catalytic converter operation or limiting cylinder output variability.

Abstract: Methods and arrangements are described for controlling transitions between firing fractions during skip fire operation of an engine in order to help smooth the transitions. Generally, firing fractions transitions are implemented gradually, preferably in a manner that relatively closely tracks manifold filling dynamics. In some embodiments, the commanded firing fraction is altered each firing opportunity. Another approach contemplates altering the commanded firing fraction by substantially the same amount each firing opportunity for at least a portion of the transition. These approaches work particularly well when the commanded firing fraction is provided to a skip fire controller that includes an accumulator functionality that tracks the portion of a firing that has been requested, but not delivered, or vice versa.

Abstract: Methods and arrangements for transitioning an engine between a deceleration cylinder cutoff (DCCO) state and an operational state are described. In one aspect, transitions from DCCO begin with reactivating cylinders to pump air to reduce the pressure in the intake manifold prior to firing any cylinders. In another aspect, transitions from DCCO, involve the use of an air pumping skip fire operational mode. After the manifold pressure has been reduced, the engine may transition to either a cylinder deactivation skip fire operational mode or other appropriate operational mode. In yet another aspect a method of transitioning into DCCO using a skip fire approach is described. In this aspect, the fraction of the working cycles that are fired is gradually reduced to a threshold firing fraction. All of the working chambers are then deactivated after reaching the threshold firing fraction.

Abstract: Methods and arrangements are described for controlling transitions between firing fractions during skip fire operation of an engine in order to help smooth the transitions. Generally, firing fractions transitions are implemented gradually, preferably in a manner that relatively closely tracks manifold filling dynamics. In some embodiments, the commanded firing fraction is altered each firing opportunity. Another approach contemplates altering the commanded firing fraction by substantially the same amount each firing opportunity for at least a portion of the transition. These approaches work particularly well when the commanded firing fraction is provided to a skip fire controller that includes an accumulator functionality that tracks the portion of a firing that has been requested, but not delivered, or vice versa.

Abstract: Systems and methods for starting an engine are described. In one example, engine cranking speed for an engine of a hybrid vehicle is adjusted in response to operating conditions. The engine cranking speed may be reduced when capability of a battery that supplies power to rotate the engine is less than an amount of power to rotate the engine at a higher speed.

Abstract: A variety of methods and arrangements for determining whether a high pressure exhaust spring is present in a cylinder of an internal combustion engine are described. For spark ignition engines, the electrical properties of the spark plug spark gap may be used to determine whether a high pressure exhaust spring is present.

Abstract: In one aspect, a skip fire engine controller is described. The skip fire engine controller includes a skip fire module arranged to determine an operational firing fraction and associated cylinder load for delivering a desired engine output. The skip fire engine controller also includes a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction. Various methods, modules, lookup tables and arrangements related to the selection of a suitable operational firing fraction are also described.

Abstract: A variety of methods and arrangements for detecting misfire in a skip fire engine control system are described. In one aspect, a window is assigned to a target firing opportunity for a target working chamber. A change in an engine parameter is measured during the window. A determination is made as to whether a firing opportunity before the target firing opportunity is a skip or a fire and/or whether a firing opportunity after the target firing opportunity is a skip or a fire. Based at least in part on this skip/fire determination, a determination is made as to whether the target working chamber has misfired. In various embodiments, if the target working chamber is identified as persistently misfiring, the firing sequence is modified so that the target working chamber is deactivated and excluded from the firing sequence. In still other embodiments, a torque model is used to detect engine-related problems.

Abstract: Methods and arrangements for transitioning an engine between a deceleration cylinder cutoff (DCCO) state and an operational state are described. In one aspect, transitions from DCCO begin with reactivating cylinders to pump air to reduce the pressure in the intake manifold prior to firing any cylinders. In another aspect, transitions from DCCO, involve the use of an air pumping skip fire operational mode. After the manifold pressure has been reduced, the engine may transition to either a cylinder deactivation skip fire operational mode or other appropriate operational mode. In yet another aspect a method of transitioning into DCCO using a skip fire approach is described. In this aspect, the fraction of the working cycles that are fired is gradually reduced to a threshold firing fraction. All of the working chambers are then deactivated after reaching the threshold firing fraction.

Abstract: Methods and arrangements are described for controlling transitions between firing fractions during skip fire operation of an engine in order to help smooth the transitions. Generally, firing fractions transitions are implemented gradually, preferably in a manner that relatively closely tracks manifold filling dynamics. In some embodiments, the commanded firing fraction is altered each firing opportunity. Another approach contemplates altering the commanded firing fraction by substantially the same amount each firing opportunity for at least a portion of the transition. These approaches work particularly well when the commanded firing fraction is provided to a skip fire controller that includes an accumulator functionality that tracks the portion of a firing that has been requested, but not delivered, or vice versa.

Abstract: A method and a system for balancing cells of a vehicle battery includes discharging charge from a highest charged cell for a discharge time period dependent on a charge difference between the highest charged cell and a lowest charged cell at a given time. The cells may be charged with the discharge charge during a charge time period.

Abstract: A variety of methods and arrangements for determining whether a high pressure exhaust spring is present in a cylinder of an internal combustion engine are described. For spark ignition engines, the electrical properties of the spark plug spark gap may be used to determine whether a high pressure exhaust spring is present.

Abstract: Systems and methods for starting an engine are described. In one example, engine cranking speed for an engine of a hybrid vehicle is adjusted in response to operating conditions. The engine cranking speed may be reduced when capability of a battery that supplies power to rotate the engine is less than an amount of power to rotate the engine at a higher speed.

Abstract: A system includes a vehicle controller having a processor and in communication with a communications device and vehicle display, the controller configured to receive a sensor input containing at least one of a fault trigger and a contextual data captured during the fault trigger. The controller may analyze, via the processor, the fault trigger to determine a fault event. The controller may determine an appropriate service center and transmit, via the communications device, the fault event and contextual data to the service center. The controller may be configured to receive an analysis report and an appointment request and output the analysis report and appointment request to a vehicle display device.

Abstract: One embodiment of an on-vehicle audio system may include at least one of a transceiver and a plug connector configured to communicatively connect to a mobile phone. The transceiver or plug connector may receive a voice signal generated by a microphone device integrated in the mobile phone. Further, the system may also include an on-board controller configured to receive an audio signal from an audio source and the voice signal from the transceiver or plug connector. The controller may be configured to interrupt the audio signal and output the voice signal on an on-board speaker.