Transmission is a transmission in the car， one of the most important components， it is by changing the transmission ratio to change the engine crankshaft torque and speed to meet the car at the starting， reversing， variable-speed driving and other driving conditions， driving wheels， traction needed to size， driving directions and different speed It is a direct impact on the engine's smooth power output and the car starts normally， as well as whether the vehicle under various road conditions enough to meet their needs and driving conditions for the smooth gear This paper studies the AL4-type 4-speed electronically controlled automatic transmission， through the constitutive principle of understanding of its structure， to address several common failure analysis and solution of the next AL4 electronically controlled automatic transmission， use and maintenance of vehicles have a very practical
