Hi,

Long time lurcher first time posting. Have found a lot of useful info on myCX5 and Mazda-3 over the year.

I have a recent issue where on occasion I get the AT light come on and the vehicle loses acceleration momentarily. the light goes off and the vehicle is back to normal.

I have since replaced the fluid (and pan since it was rusted out), it seemed to make the issue go away for a few days, but it's now back. I brought it into our local Mazda dealership and they were not able to have the issue reproduce. They recommended a bunch of things that were totally unrelated (brakes, sway bar linkage and others). I've seen a few people on other Mazda models mention they change some sensors and it seemed to fix the issue. I'm not sure where to go on this one since I cannot find a transmission specific shop anywhere near me to have a look.

Hoping someone might have some idea/advice or may have seen this issue before. the car is paid and I'd rather not have the swap out the tranny, but I feel like I'm randomly throwing money at the thing.

Once the light goes off there is no remaining code, so even a code reader is not helpful.

 

How long since your last Trans Fluid and FILTER Change?

 

did the fluid change, not 100% on the filter. Given it's not listed on the invoice I have to assume they only replaced the fluid.

 

I'll assume even after the pan change, that you've checked that the fluid level is fine.
Faulty AT codes come from the transmission module not the engine module.
You'll need the code(s) to find your problem which can be any of the following.
P0218, P0613, P0614, P0700, P0706, P0715, P0720, P0729-P0736, P0750-P0770
Relating to: Transmission temperature sensor, faulty TCM, valve body, solenoid, transmission range sensor, PCM (Rare), transmission speed sensor, bad transmission.
Without knowing what codes, you can easily spend more money on parts than getting another transmission.

 

I'm bringing it into a actual transmission shop in 2 weeks. It was the earliest they could take it. This is what I should have done in the first place instead of going to the stealership.
Still a little pissed at the dealership for not doing what we asked them to, which was to diagnose the transmission issue, not tell us the car needs a freaking cabin air filter, rear brakes, sway bar linkage and an engine air filter. They've lost any chance of me ever purchasing a vehicle from them.

 

The ECU/TCM has an update listing that you should check into which could account for that described condition, maybe? I need to add you to the list of transmission concerning by following the poorly conceived transmission service scheduling done by many auto manufactures concerning their automatics. Iam sure as a lurker you have read a few threads about transmission problems and how to prevent most of them?

 

So we have an appointment on Tuesday to have this looked at. I went to move the car in the driveway today and it would not start. P0101 tcm module but communicating. Had to get it towed over to the shop so they can look at it on Tuesday. And now we wait to see what the verdict is. Ugh

 

A long awaited update. Got the car back from the transmission place. They ended up replacing the parking switch (the one that senses when the car is in park) and they've done 3 hours of diagnostic driving and were not able to have it happen again. I'm hoping this was oit. They said it could be that it was in bad shape enough that the current wasn't getting thorough properly to the TCM. Fingers crossed this was it. I knew it was flaky, but never thought this could have been the issue. Would have replaced it for like $40 and saved hundreds.

 

Sounds like that was the issue.
You've given others here something to check should they have a similar issue.
We can all thank you for that.

 

*UPDATE* The issue has re-surfaced. So unfortunately we are now back to square one. The issue always comes up at low speed within the first few gears (1-2 seemingly). The AT light still comes on, the gear position indicator no longer disappears, or so it seems. Still no code to be found on through ODBII reader.