Methods and systems for engine shut-down control

摘要

An example method of operation comprises, selectively shutting down engine operation responsive to operating conditions and without receiving an engine shutdown request from the operator, maintaining the automatic transmission in gear during the shutdown, and during an engine restart from the shutdown condition, and with the transmission in gear, transmitting reduced torque to the transmission. For example, slippage of a forward clutch of the transmission may be used to enable the transmission to remain in gear, yet reduce torque transmitted to the vehicle wheels.

主权项

1. A method of controlling a vehicle powertrain, comprising:
shutting down an engine responsive to operating conditions and without receiving a shutdown request from an operator, the shutdown including engine idle-stop; maintaining an automatic transmission in gear during the shutdown; and during an engine restart from the shutdown, and with the transmission in gear and grounded, transmitting reduced torque to the transmission by increasing slippage of a transmission clutch to adjust a degree of grounding, wherein transmitting reduced torque to the transmission further includes actuating the transmission to internally lock the transmission and block transfer of input torque to vehicle wheels.