what is electronically controlled transmission?
Older Transmissions were constructed to shift with Oil pressure. They did not shift smoothly and sometimes due to wear they would not shift at all. The newer transmissions are conrolled by the On Board computer. They are set to shift according to the speed of the drive shaft. Some cars have two speed switches that work off of the rear of the Transmission. Some cars only have one. There is more than one item that controls the speed at which the auto will shift. Electrically controlled shifting is smoother and less trouble some than the older method.
Well you got alot of it but here are a couple additions. Older transmissions used a combination of vacuum and hydraulic pressures. This would in turn use the oil in the tranny to push on certain pistons at certain times. This would make for rough shifting and sometimes no shifting. The electronically controlled transmission uses a computer to do the shifting through the use of solenoids. The computer does this with the inputs from various sensors such as: Speed sensor, Throttle position sensor, Manifold pressure sensor, and others that I cannot think of at this point. Very complicated indeed.
On earlier automatic transmission, the automatic feature is controlled by a group of valves working together to control the shifting sequences. electronically controlled transmission as the name implies,,it is controlled electronically by a computer. instead of using the old valves from old transmission they use electronic softwares to control shifting sequences. some of the added parts are speed sensors, solenoid valves and control unit which is the memory. some advantages of electronic transmission are the following, lesser in volume,lighter in weight easy to maintain and repair,, most parts are accessible externally smooth in shift and quicker in reaction