Powertrain torque control during a transmission shift

A vehicle comprising:

• an engine configured to generate power;
• a transmission (i) configured to transfer power from the engine to at least one drive wheel to propel the vehicle and (ii) having a plurality of clutches configured to shift the transmission between a plurality of gear ratios;
• an accelerator pedal configured to generate a command corresponding to a desired engine torque in response to depression of the accelerator pedal;
• and
• a controller programmed to,
• in response to a command to shift the transmission, reduce a torque of the engine from the desired engine torque to a reduced value based on a flare at an input to the transmission during the shift,
• in response to the reduced value exceeding a threshold, retard an engine spark and maintain operation of all cylinders of the engine to reduce the torque of the engine during the shift, and
• in response to the reduced value being less than the threshold, retard the engine spark and shutdown at least one cylinder of the engine to reduce the torque of the engine during the shift.

A vehicle comprising:

• an engine configured to generate power;
• a transmission configured to transfer power from the engine to at least one drive wheel to propel the vehicle;
• and
• a controller programmed to,
• in response to a command to shift the transmission and a corresponding command to decrease a torque of the engine to less than a threshold corresponding to a spark retard limit during the shift to compensate for flare at an input to the transmission, (i) retard an engine spark at the spark retard limit to reduce the torque of the engine to the threshold and (ii) shutdown at least one cylinder of the engine to further reduce the torque of the engine to less than the threshold during the shift, and
• in response to the command to shift the transmission and a corresponding command to decrease the torque of the engine to greater than the threshold during the shift to compensate for flare at the input to the transmission, (i) retard the engine spark at less than or equal to the spark retard limit and (ii) maintain operation of all cylinders of the engine to reduce the torque of the engine to greater than the threshold during the shift, wherein the torque of the engine is reduced based on a rate of change of the flare.