Daimlerchrysler Corporation

Chrysler Group LLC

Andrew J Harkenrider

Gerald L Holbrook

Michael J McNeil

Mark J Duty

John M Rzepecki, Ii

Michael Fingerman

Yi Cheng

Michael L Plunkett

A system for controlling the engagement and disengagement of one or more clutches that are adapted to operatively connect an engine and an automatic transmission includes a control device for determining if a negative torque condition exists and for providing an output or signal to decrease the rotational speed of the engine in response to the determination of the existence of the negative torque condition.

Automatic transmission with neutral coast down feature

A method of determining the shift lever position of an electronic automatic transmission system by identifying the mode of transmission operation selected by the driver of the vehicle to provide hysteresis between the park, reverse, neutral, drive and low positions, to permit improved performance and response of the controller and to permit limited operation of the controller upon the occurrence or detection of a fault effecting the performance of the transmission. Such faults include the loss of a PRND2L sensor and the loss of one or more sensors indicative of the dynamics of the vehicle or hydraulic circuit.

Shift lever position logic

The present invention provides a method for shifting from a first gear state to a second gear state which holds one element at a predetermined level until the second reaches its fill volume. In this method, one element is applied while the other element is released. The element which reaches its fill volume first is held at a control limit. This control limit is defined by a volume between the first clutch element and a predetermined point above the fill volume of the first clutch element. This clutch element is then maintained at within the control limit until the other clutch element reaches its fill volume. The maintained clutch element is then released shortly after the other clutch element has reached its fill volume. This method ensures that neither fighting or slipping occurs between the two elements.

Element overlap control for an automatic transmission

The present provides a shutdown shift schedule which allows a vehicle driver an increased number of gear states to increase driveability. This method monitors the gear state conditions indicative of the gear state which said automatic transmission is in. When the shift state conditions vary from predetermined standards, the controller uses the shutdown shift schedule in place of the shift schedule for changing gears of the automatic transmission. This shutdown shift schedule is adapted to allow a 3-1 shift when the shift solenoid is in a shift D position and the shift state is 3. The shutdown shift schedule is also adapted to allow a 3-2 shift when the shift state is 3 and the shift solenoid is in the shift 2 position.

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Rochester Hills, MI, United States of America

Andrew J Harkenrider