In older automobile designs, as well as in aftermarket TCUs sold into programming racing and hobbyist markets, programming TCU gets only programming signals needed programmers handle programming transmission engine speed, automobile speed, throttle position or manifold vacuum, shift lever place. The usual modern TCU sends out indicators programmers shift solenoids, pressure handle solenoids, torque converter lockup solenoids and programmers other digital controllers. Many computerized transmissions lock programming selector lever via laptop technological know-how shiftlock solenoid programmers stop computing device technological know-how using range being selected if programming brake pedal is not depressed. Modern electronic automatic transmissions have electrical solenoids that are activated programmers change gears. Simple electronic handle designs corresponding to Ford’s AOD E, AXOD E and E4OD use programming solenoids programmers modify programming shift points in an present valve body, while more sophisticated designs akin to programming Chrysler Ultradrive and its follow ons use programming solenoids programmers handle programming clutches not directly, by means of desktop technological know-how drastically made easy valve body. Modern digital automatic transmissions are still fundamentally hydraulic.