Hey everybody.
I've already posted about this problem a few months ago and I still haven't figured out the problem.
Basicly I have a mazda 6 3.0L 2004. The mazda ran fine for about 5 to 6 months while I had it and then It all of a sudden kicked on the AT light (automatic transaxle) and then started shifting straight to 3rd at start up and would shift to 4th but it wouldnt shift under 3rd for anything. I started doing research and alot of stuff said shift soleniods so I started there and that didn't work BUT every now and then at stop lights or signs it would shift to 1st but stall as soon as it did if I didnt stay on the gas. A close friend of mine said he could hook the car up to his diagnostic machine (2300$ shop quality machine) so we did and it was shootin out some failures but he said that the source of the falures was the PCM so I went to a junk yard to find one and I found out that the PCM and TCM used to be the same thing and now it's not and that instead of the PCM being the problem it's more Likely the the TCM is the colprate. A PCM (Powertrain Control Module) is 400 to 500 bucks and the TCM (Tranmission Control Module) is 150 and my buddies diagnostic machine can inhale and exhale so I don't know if someone else knows about this problem and can help or have so advice if I left something to question just ask and I'll do my best to explain better.

 

The AT light indicates a problem with the trans. The trans moves to a "limp" mode. In limp mode, the trans shifts into 3rd gear to allow you to safely move the car out of the roadway. It's not meant to be, and shouldn't be, driven in limp mode. Anything from a turbine speed sensor to bad wire contact could trigger the AT light. Test, not guess, unless you have an unlimited wallet and enjoy throwing parts at it until one fixes it. What code or codes are you pulling? It may be a TCM, but without knowing what DTC is set, there is no way of suggesting a course of action. Be glad to help if I can.

 

I hoestly can't remember the code but I remember it's a shift soleniod C code but I replaced it and then I replaced the whole kit. So it's not that.

 

Had one haunt me on a MZ3, same concern with shift solenoid C. Long story short, the connector, pin, on the harness side at the TCM, had a poor fit condition. It haunted me because it wasn't a "hard" fault. Very random actually. Just look at all your connectors and make sure your getting a good connection. Could very well be TCM, just don't want you to over look something.

 

Hmmm well does anyone know where the PCM is located becuase I can't find it. I don't have the manual for the car..