Hi, I bought a used Mazda 3 in October. (as is with a small extended warranty). Within 3 weeks the transmission started acting up.. dropping from 5th to 3rd gear at constant highway speeds. The A/T light would come on when it was acting up, but would not store the code. I took it to the dealer and all they would say is that it needed a new transmission but couldn't tell me why. So, I then took it to a transmisssion shop. Upon instection they determined that the hydraulic system was shot in the car. They rebuilt the transmission. I went to the shop and picked up the car. Within 10 miles of leaving the shop, it was doing the same thing it was and this time threw an engine code. I took it to Autzone and had the code read. It was U0101 which is basically the TCM not communicating with the transmission. Later, the light went out and the car was acting fine. I decided to drive the car around and check it out some some. It acted fine until I used the manual mode. Then A/T light came on, the check engine light came on, and drove erratic. I called the transmission shop and they said that it may need the computer reprogrammed. However, after dropping it off, they read 5 engine codes. I can't remember them all, but one was the TCM not communicating with the transmission, ABS system problems, power steering problems, a CAS problem, and I can't remember the 5th one. Anyone else have this problem? The transmission shop said they are going to call the dealer to see if this is an issue. The problem is I had the car at the dealer, and they couldn't diagnose much of anything. I am out a ton of money, am broke right now, and it is right before Christmas! UGH@ I need help!

 

Hello, I have the same problem and was wondering if your car got fixed and what was repaired?

Thanks

 

Yes that initial problem was fixed when the TCM was changed in the car. The transmission shop I went to was a joke and who knows what else they have done tot he car. I still love my Mazda3, but I will say that you need to take it to someone who knows what they are doing or you will have problems later. Good luck!

 

sorry to hear about what you had to go through, but thanks for your response. Now i'm confident its the TCM that has to be replaced.

thanks