What does TCU failure mean?
2 Answers
TCU failure refers to an automatic transmission malfunction. Below is an introduction to TCU failure: 1. TCU, the automatic transmission control unit, consists of a 16-bit or 32-bit processor, signal processing circuits, power drive modules, etc. It is commonly used in AMT, AT, DCT, and CVT automatic transmissions to achieve automatic shifting control, making driving simpler. 2. Common symptoms and solutions for TCU failure: (1) Oil leakage: Oil seeps from the transmission housing or oil pan. One cause is aging or poor sealing of the seals, while another is casting defects in the housing. The solution is to replace the seals or the transmission housing. (2) No response when shifting into gear: The vehicle does not move after shifting into D or R and releasing the brake. This is often caused by damage to the input shaft or reverse clutch, or failure of the D or R brakes. The solution is to replace the damaged clutch or brakes.
My experience with a TCU malfunction was that the transmission control unit had issues, meaning the computer module responsible for automatic gear shifting stopped working. The symptoms were obvious: the car would jerk or hesitate during gear shifts, and in severe cases, it could even get stuck in a particular gear. That time, when I was driving on the highway, it felt like the car was protesting, frequently shaking or losing power—it was truly nerve-wracking. Possible causes include software errors, short circuits on the circuit board, sensor failures, or even unstable voltage. Not fixing it promptly could affect the entire transmission and engine, increasing repair costs. I immediately went to the 4S dealership, where they used diagnostic tools to check and found that the software needed an update. It was fixed quickly. Regular maintenance of the transmission fluid and avoiding sudden acceleration can effectively prevent such failures and extend the car's lifespan.
