Abstract: A system and method for controlling gear ratio changes in an automatic transmission includes an electronic microprocessor, an electronic memory accessible to the microprocessor, solenoid-operated shift valves, pressure actuated friction clutches and brakes, a variable force solenoid-operated valve, a torque converter bypass friction clutch, and control algorithms that produce output signals to control the state of the solenoid-operated valves. The vehicle speed and engine speed at which upshifts and downshifts occur, according to a standard gear shift schedule, is compensated for loss of engine torque at conditions that differ from the conditions at which a reference shift schedule is defined. Vehicle speed is compensated for torque variation with reference to the ratio of current calculated engine torque divided by current engine output torque.

Abstract: A power steering system for a wheeled vehicle comprising a fluid motor connected to dirigible wheels of the vehicle, a power steering pump and a steering valve structure situated in flow delivery and flow return passages that connect the pump with the fluid motor, the valve structure including a pilot-operated solenoid valve means that controls the bypass flow between the supply and return sides of the pump wherein a solenoid actuator is adapted to apply a vehicle speed sensitive force on a pilot valve portion of the valve which develops valve actuating forces on a flow control portion of the valve wherein the latter is speed conscious only and does not depend upon flow to and from the pump nor upon the steering pressure for the fluid motor.