
Automatic transmission failure is caused by a malfunction in the transmission's mechatronic control unit. The automatic transmission consists of a torque converter, mechanical transmission, shift actuator, hydraulic control system, and electronic control system. The transmission, also known as the gearbox, is a mechanism used to alter the speed and torque from the engine, capable of fixing or changing the gear ratio between the output and input shafts. Automatic transmissions are categorized into: 1. Stepped transmission; 2. Continuously variable transmission (CVT). Transmission maintenance methods include: 1. Regularly check the fluid level; 2. Avoid skipping gears when upshifting; 3. Do not force the transmission into neutral; 4. Do not shorten the idle warm-up time; 5. Avoid gear grinding when shifting.

I've been driving for over 30 years and have seen too many automatic transmission failures. The most common cause is transmission fluid issues - low fluid level or deteriorated/dirty fluid clogging passages, leading to poor lubrication and accelerated clutch plate wear. Electronic control system failures are also widespread, such as faulty speed sensors or shift modules sending incorrect signals, causing rough shifting or gear jamming. Overheating due to inadequate cooling is another critical point, with prolonged driving in traffic jams or clogged radiators causing internal metal components to expand and seize. Driving habits like sudden acceleration and hard braking accelerate component wear. Mechanical parts like planetary gears or valve bodies aging and failing can also cause slippage. I recommend checking fluid level and clarity every 30,000 km, complete fluid and filter replacement every 60,000 km, and addressing any issues early at professional shops before complete failure occurs.

As someone who frequently works with vehicles, I can say that automatic transmission failures have diverse root causes. Low fluid levels or oxidized/contaminated fluid can lead to lubrication failure, causing wet clutch plates to burn and slip. Faulty electronic components like position sensors may cause the control module to misjudge shift points, resulting in delays or skipped gears. Sticking valve bodies can obstruct hydraulic flow, affecting shift smoothness. Mechanical issues such as gear wear or oil pump failure can cause insufficient pressure. Overheating is particularly critical - poor heat dissipation during frequent stop-and-go traffic can cause metal deformation. Simple self-checks: Be alert if you notice jerky shifting, unusual noises, or slipping after startup. Using a diagnostic tool to read trouble codes can pinpoint issues accurately. Addressing problems early saves both money and time compared to major overhauls.

My car had an automatic transmission issue, which was quite troublesome. It might be due to low oil level from leakage, or dirty oil that wasn't changed regularly. While driving, I noticed hesitant gear shifting, slipping, and abnormal buzzing noises. The electronic sensors malfunctioned, making it impossible to control the gears properly. Prolonged traffic congestion led to overheating, causing internal jamming. Pay attention to these symptoms and get it repaired early. Maintain it well by changing the oil every two years.


