Daimlerchrysler Corporation

Colt R Correa

Maurice B Leising

Gerald L Holbrook

Hussein A Dourra

Shean P Huff

David Parenti

Rita D Hollingsworth

Scott A Miller

An interactive engine and automatic transmission control system is provided wherein spark and air control are used to control engine speed to maintain a small positive torque on the transmission before and after coast down shifts. More particularly, a transmission controller is electrically coupled to an engine controller in a motor vehicle such that information can be passed therebetween. Such information includes a start of shift signal, a phase of the shift signal (i.e., clutch release phase, speed change phase, or clutch application phase), and a shift complete signal. In addition, the transmission controller identifies the type of shift that is occurring (i.e., fourth gear to third, third to second, or second to first), transmission oil temperature and the acceleration (braking) rate of the vehicle to the engine controller. During the three phases of a coast down shift, air flow control is used to supply an appropriate amount of air to the engine so that closed loop spark control can be used to adjust the speed of the engine. By maintaining the engine speed slightly above the turbine speed just before and just after a coast down shift, very little torque is transmitted through the transmission during the shift. As such, the coast down shift is practically imperceivable to the driver.

Interactive engine and automatic transmission control

The present invention provides a device for prohibiting upshift on an automatic transmission which has a controller adapted to select a gear ratio of the automatic transmission. The controller receives an output speed signal representative of a speed of the vehicle and throttle signal representative of a throttle position. Based on this information, the controller prohibits the automatic transmission from upshifting when the throttle position changes from a substantially open position to a substantially closed position at a rapid rate.

Method and apparatus for controlling upshift on an automatic transmission

The present invention provides a method for determining fill volumes of a plurality of clutch elements in an automatic transmission wherein each clutch element is applied in a predefined order and the fill volume of each clutch element is obtained by determining when the rotational speed of the engine varies from the rotational speed of the transmission's turbine by a predefined amount. The plurality of clutch elements comprises at least a 2C, 4C, UD, OD, and LR clutch element.

Quick learn procedure for fill volumes of an electronically controlled

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Lake Orion, MI, United States of America

Colt R Correa