摘要 |
A vehicle and engine control system controls engine torque to maintain positive torque at a transmission input to minimize the transmission gears from separating. By maintaining a positive engine torque, operation of the transmission in or through the zero torque, or lash, zone, is minimized. This minimizes poor vehicle driveability that would otherwise result from operation in the lash zone. The control systems uses closed loop control based on a desired and actual turbine speed ratio, or slip ratio, to provide positive torque to the transmission.
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