Abstract: A multi-speed planetary transmission is operable in at least nine forward speed ratios, at least one reverse speed ratio, and at least one neutral speed ratio. A hydraulic control system for the transmission includes a hydraulic default control system and is operable to a default configuration when a default condition occurs during operation of the transmission. The hydraulic control system defaults to a forward default gear ratio during operation of the transmission in a first forward speed ratio and defaults to a default neutral speed ratio during operation of the transmission in a reverse speed ratio when a default condition occurs. The default condition may be a transmission control module (“TCM”) power failure.

Abstract: A multi-speed planetary transmission is operable in at least nine forward speed ratios, at least one reverse speed ratio, and at least one neutral speed ratio. A hydraulic control system for the transmission includes a hydraulic default control system and is operable to a default configuration when a default condition occurs during operation of the transmission. The hydraulic control system defaults to a forward default gear ratio during operation of the transmission in a first forward speed ratio and defaults to a default neutral speed ratio during operation of the transmission in a reverse speed ratio when a default condition occurs. The default condition may be a transmission control module (“TCM”) power failure.

Abstract: An electro-hydraulic control system is provided for a transmission, which is preferably a countershaft transmission, that has a three-position dog clutch actuator valve to control the position of a three-position dog clutch. At least one of the positions of the dog clutch actuator valve is established by pressurized fluid directed to the dog clutch actuator valve by two logic valves, both of which are controlled to direct pressurized fluid elsewhere in the hydraulic control system, as well.

Abstract: An electro-hydraulic control system is provided, preferably for a countershaft transmission, that uses logic valves to multiplex trim systems to more than one torque-transmitting mechanism, thereby minimizing the number of required components. Additionally, the electro-hydraulic control system preferably has more than one failure mode so that the transmission operates at a respective predetermined speed ratio in the event of an interruption in electrical power.

Abstract: An electro-hydraulic control system is provided with a diagnostic system that uses extensive multiplexing of pressure switches to reduce the number of required components. The control system includes a controller with a pressure switch diagnostic system having first, second, third and fourth pressure switches each having a high and a low logic state, first and second logic valves each movable between a respective first position and second position, and first, second, third and fourth trim valves each movable between a respective first position and second position. The pressure switches are multiplexed to report one of the high and low logic state to the controller in accordance with a relatively high and low fluid pressure, respectively, at different ones of the trim valves and logic valves, thereby enabling a determination of a change in or failure to change position of the respective the trim valves or logic valves.

Abstract: A control system operable to engage a torque transmitting mechanism, the control system having at least one variable bleed solenoid valve operable to selectively provide pressurized fluid to selectively engage at least one torque transmitting mechanism. An electronic control unit is also provided to provide control to the at least one variable bleed solenoid valve. The electronic control unit commands the variable bleed solenoid valve to provide the pressurized fluid to the at least one torque transmitting mechanism for a first predetermined time and to subsequently substantially disallow the pressurized fluid to the at least one torque transmitting mechanism for a second predetermined time subsequent to the first predetermined time. The electronic control unit subsequently commands an intermediate pressure level to trim the torque transmitting mechanism into engagement. A method for providing engagement to the torque transmitting mechanism is also provided.

Abstract: An electro-hydraulic control system is provided for a transmission, which is preferably a countershaft transmission, that has a three-position dog clutch actuator valve to control the position of a three-position dog clutch. At least one of the positions of the dog clutch actuator valve is established by pressurized fluid directed to the dog clutch actuator valve by two logic valves, both of which are controlled to direct pressurized fluid elsewhere in the hydraulic control system, as well.

Abstract: An electro-hydraulic control system is provided, preferably for a countershaft transmission, that uses logic valves to multiplex trim systems to more than one torque-transmitting mechanism, thereby minimizing the number of required components. Additionally, the electro-hydraulic control system preferably has more than one failure mode so that the transmission operates at a respective predetermined speed ratio in the event of an interruption in electrical power.

Abstract: An electro-hydraulic control system is provided, preferably for a countershaft transmission, with a diagnostic system that uses extensive multiplexing of pressure switches to provide accurate information regarding the position of valves within the control system while minimizing the number of required components.

Abstract: The present invention provides a controlled leak within the clutch feed passage of the hydraulic clutch control system. The controlled leak will operate to provide compliance to the hydraulic clutch control system and may prevent pressure overshoot conditions during clutch trim. The controlled leak is only present during clutch trim and is discontinued during full apply conditions.