Management of operation of motor vehicle internal combustion engine and gearbox for leaving a motor vehicle freewheel running condition with internal combustion engine off

An automotive electronic control unit for at least one of an internal combustion engine and a powertrain of a motor vehicle programmed to:

• control the powertrain to stop the internal combustion engine and disengage a drive line, whereby the motor vehicle enters a freewheel running condition, and crank the internal combustion engine and engage the drive line, whereby the motor vehicle leaves the freewheel running condition;
• and
• control the drive line during an internal combustion engine run-down consequent upon the motor vehicle entering the freewheel running condition, to cause engagement of a gear appropriate for inertial cranking of the internal combustion engine before the internal combustion engine leaves a self-sustaining operating condition, while the clutch is kept disengaged, wherein, if the motor vehicle freewheel running condition with internal combustion engine off is to be left during an internal combustion engine run-down consequent upon the motor vehicle entering the freewheel running condition with internal combustion engine off, control the powertrain so as to:
• if the internal combustion engine is in a self-sustaining operating condition and engagement of a gear appropriate for inertial cranking of the internal combustion engine has been started but is not yet completed:
• wait until the internal combustion engine has left the self-sustaining operating condition and engagement of the gear appropriate for inertial cranking of the internal combustion engine has been completed and then cause engagement of the clutch, whereby resulting in the internal combustion engine being inertially cranked, or
• cause cranking of the internal combustion engine by means of fuel injection, cause abort of engagement of the gear appropriate for inertial cranking of the internal combustion engine, cause engagement of a gear appropriate for the motor vehicle operating condition at the moment in which the internal combustion engine is cranked up, and, finally, cause engagement of the clutch.

A motor vehicle comprising a powertrain including an internal combustion engine, a servo-actuated drive line in turn comprising a gearbox and a clutch, and an automotive electronic control system, wherein the automotive electronic control system is configured to:

• control the powertrain to stop the internal combustion engine and disengage the drive line, whereby the motor vehicle enters a freewheel running condition with internal combustion engine off, and crank the internal combustion engine and engage the drive line, whereby the motor vehicle leaves the freewheel running condition with internal combustion engine off;
• wherein, if the motor vehicle freewheel running condition with internal combustion engine off is to be left during an internal combustion engine run-down consequent upon the motor vehicle entering the freewheel running condition with internal combustion engine off, control the powertrain so as to:
• if the internal combustion engine is in a self-sustaining operating condition and engagement of a gear appropriate for inertial cranking of the internal combustion engine has been started but is not yet completed:
• wait until the internal combustion engine has left the self-sustaining operating condition and engagement of the gear appropriate for inertial cranking of the internal combustion engine has been completed and then cause engagement of the clutch, whereby resulting in the internal combustion engine being inertially cranked, or
• cause cranking of the internal combustion engine by means of fuel infection, cause abort of engagement of the gear appropriate for inertial cranking of the internal combustion engine, cause engagement of a gear appropriate for the motor vehicle operating condition at the moment in which the internal combustion engine is cranked up, and, finally, cause engagement of the clutch;
• and
• control the drive line during an internal combustion engine run-down consequent upon the motor vehicle entering the freewheel running condition with the internal combustion engine off, to cause engagement of a gear appropriate for inertial cranking of the internal combustion engine before the internal combustion engine leaves a self-sustaining operating condition, while the clutch is kept disengaged.

A non-transitory computer readable medium comprising software loaded onto the non-transitory computer readable medium in an automotive electronic control unit of an automotive electronic control system, wherein the software loaded onto the non-transitory computer readable medium is designed to cause, when executed, the automotive electronic control system to:

• control the powertrain to stop the internal combustion engine and disengage the drive line, whereby the motor vehicle enters a freewheel running condition, and crank the internal combustion engine and engage the drive line, whereby the motor vehicle leaves the freewheel running condition;
• wherein, if the motor vehicle freewheel running condition with internal combustion engine off is to be left during an internal combustion engine run-down consequent upon the motor vehicle entering the freewheel running condition with internal combustion engine off, control the powertrain so as to:
• if the internal combustion engine is in a self-sustaining operating condition and engagement of a gear appropriate for inertial cranking of the internal combustion engine has been started but is not yet completed:
• wait until the internal combustion engine has left the self-sustaining operating condition and engagement of the gear appropriate for inertial cranking of the internal combustion engine has been completed and then cause engagement of the clutch, whereby resulting in the internal combustion engine being inertially cranked, or
• cause cranking of the internal combustion engine by means of fuel injection, cause abort of engagement of the gear appropriate for inertial cranking of the internal combustion engine, cause engagement of a gear appropriate for the motor vehicle operating condition at the moment in which the internal combustion engine is cranked up, and, finally, cause engagement of the clutch;
• and
• control the drive line during an internal combustion engine run-down consequent upon the motor vehicle entering the freewheel running condition, to cause engagement of a gear appropriate for inertial cranking of the internal combustion engine before the internal combustion engine leaves a self-sustaining operating condition, while the clutch is kept disengaged.