Hello everyone,
This is a bit of a last resort and i am just trying to see if anyone else out there has had this problem or has a possible solution to what it may be. Here we go... I have a 2007 Mazda3 5 door 2.3L AT 5 speed with a little over 84k. I have had steelership do all oil changes and i did a trans oil/filter at 35k and 81k mi. last Sat., it started dropping from 5th to 3rd at highway speed. This was in "D". I tried putting it in manual and it limped the remaining 6 mi home without issue. Sunday was a different story, it did it in Manual and "D". Main offending gears were 3rd, 4th, and 5th in "D" and manual. Sunday night i changed the trans fluid again (5 quarts not a full flush). Fluid was a little dirty but not that bad. Just wanted to make sure it wasnt some filter issue. I took it out at about 130am after finishing (different long story behind that) and it did it almost immediately in the same gears and conditions, like less than 1000 ft of driving. I took streets on Monday and took it to the steelership on Tuesday at 830 AM.
I explained that it does it always after it is at operating temp and sometimes then it is cold, the check enginge light was on, the DCS light comes on when it does it and stays on after the 2nd or 3rd time, and the light that shows what gear i am in disappears sometimes when it happens. Steelership said that it needed ECU update and had a loose harness at the cluster. This was Late Tuesday. On Wednesday they said they were finishing that up and there were some other repairs i had going on that were the a/c control and stereo. The parts would be 2 days so it would be ready friday (yesterday).
So i pick it up Friday and everything processed. Checked the paperwork and it said that trans fluid was "dirty", odd after changing it on sun but ok. I get into the vehicle and the check engine light was on. I told them about it and he said the tech had forgotten to clear the code and if it stayed on they would clear/check it on mon/tues when i could come back in. So i drive home and no events. Check Engine light goes off as it should after 2 cycles with no code, and i go home. Next morning(today) i start it to warm it up and the check engine light and the DSC light are on. Again i get about 1/4 of a mile omw to drop kids off at parents before going to work and the trans starts doing it all over again. It has done it all day no matter where i go or how i drive it. I am not hard on this vehicle and have 2 questions(thanks for bearing with me):

1. When you update the ECU does that remove the engine codes, like totally re-write the memory? I ask because if it does, then the code happened again after they flashed it, or they never really did anything.
2. WHAT COULD BE WRONG HERE??????


Thanks in advanced for your advice.

PS i will try and post a little video of what it was doing

 

here is the video i was promising. check out the times 1:40, 4:00, and 4:20 to see waht is going on.

 

Hi Ryan,

I have never had this problem... but it sounds like it could be something in the transmisison itself? Although at your mileage I would never have guessed it... but maybe the car's transmission is losing its grip on its gear changes? The auto tranny uses a series/parallel of brakes and clutches to manoever the gear ratios. If somehow those brakes/clutches were to wear they would no longer be able to do their job appropriately.

On the other side of that issue, it is the ECU that controls the brakes/clutches and as such could have been the problem... although you said they had that wiped and re-freshed.

Which is why it is leading me to think that it is hardware not software.

Also, this wear could be what is causing your tranny fluid to get so dirty so fast. You mentioned they said it was dirty even after you had just replaced some of it... (although could also be them trying to get some money out of the job)

Anyway, hope this helps... my suggestion is to have someone take a look at the actual transmission (physically)

P.S. - You mentioned the check engines light come on, was that before the weird downshift or after?

 

Thanks for the reply. The CEL was not on prior to the first instance of the issue. It has been on since. Some mornings the light is not on, however as soon as the issue occurs it trips. I have quite a bit of automotive background, just not with computer controlled vehicles. I have a '70 camaro also and the only work i have not done on it was the line hone on the block. I built the trans with a friends dad who owns a trans shop. So i have an idea of how the clutches, bands and gears work in a trans. I took it into the dealership today, showed them multiple videos, and they were very timid with how they were aproaching the situation.
They did offer to have me take the tech for a test drive, and due to the wet road conditions from recent rain i declined as i did not feel safe driving the vehicle with annother person in the care with the issue and possibly the DSC/traction controll malfunctioning. They also verified that the code should have been cleared with the flash, and had no answer as to why the CEL was on when i picked it up. When i posed the fact that it tripped when they were driving it after and they were negligent in checking it they declined to respond. Also when i brought up the fat that the fluid was dirty after two days i posed 3 reasons:
1. the clutches/bands were experiencing extreme ware, and this should have been a red flag.
2. They put reused fluid in the vehicle to blame it on, or get additional service out of me.
3. Dirty fluid can have a binding effect in the clutche and help to "lessen symptoms of a slipping AT trans"
again they declined to discuss this and said they would contact me throughout the day with updates. I will try and update this post with any new info.

What i will say is that they have provided alternate transportation for me and i would like to be honest about the accounts with this dealership.

I will post the info i get from them so it may help anyone else who may be experiencing the same issues.

 

There are pressure solenoids that maybe affecting the clutches, maybe not giving enough pressure to hold the clutch.
I cringed every time I saw your rpm go up, and the mph stay steady.
It’s a pressure problem, but it can wipe out clutches quickly
What codes came up?

 

well i got a call from the service department today saying that it was all done. They said that the harness behind the fuse block was loose and that they road tested it for about 40mi with no occurence. The codes on the work order were u1900,u2023,u0101. I am going ot ask them where this "Connection" is and post what pics i can in case this is the fix. I also plan on doing a full flush on trans this weekend to see if the at fluid gets dirty over the comming weeks.

Thanks Again!

 

well went into the dealership today and picked up car. They said that the"connector C04, at engine fuse box, found loose terminals gray/red and blue/red, tightened and re-checked, road tested ok, no codes returned."

I drove the vehicle aprox 1.5mi and was at a stop when the CEL, AT and DSC light all came on and the 1st gear indicator disappeared. When when indicator showed 1st again the AT light went off. Took it right back and left it running so they could see CEL and DSC lights (DSC clears sometimes when you turn car off)...

Any one know why a connection would come loose unless it was damaged? I had an alarm put in at 3k mi but i doubt that that is it... Never had any work done that needed the connections removed.

EXTREMELY FRUSTRATED!!!!!

 

on a side note, i also noticed that on the original work order, they never test drove it, Mi in was 84640 and Mi out was 84640...

 

I think Mazda has poor connectors; I had a trany issue that was also a connector problem.

here is your C04 connector

 

Great diagram! Only thing is they said connection was under the fuse block... I am really starting to think that all of these techs at this dealership are not too bright.

I called yesterday and they said they "Tightened" connections again, road tested and it did it to them again so they are still"tracking it down." I asked the service write if they are just chasing down one at atime or if they were tightening up everything that leads to the TCM? I told him that what i am used to is "Nut and Bolt" setups where you check everything in the system or that is attached to it, and if it does it again then it is hardware no the tech... He didn't seem amused. Tried to say they were working very hard on the car, and I asked him how many times this has to happen before they can say it is a problem with the harness? He said there is no fixed number but they may start exploring that today.

Anyone know whey they might be being so reluctant about fixing a part rather than "tightening" connections??? I mean they have had my car for 5 days and have provided me a $25/day rental for 4 of them. You'd think they would want to stop the bleeding.

 

Turns out it is the traction control module(TCM). i will post the final outcome next week when i get it back. They are trying to rook me for extra monies... details next week.

 

Hi Ryan

I was wondering how everything went with your Mazda. My Mazda is doing EXACTLY the same thing! I've just forked out $814 and the dealership said it was fixed, but it wasn't. 1km up the road and it faulted 3 times. I took it back, and they called me and said 3 people had separately taken it for 15 minute trips and it didn't fault. I was then told it was MY driving that was making it happen. As I was at work at the time, they said they would come pick me up and let me drive it for them to show them what happens. I get a call whilst I'm waiting for them to turn up, and the lady says it faulted whilst the mechanic was sitting in it, just about to leave the dealership. YAY!!! They call me later saying that I need to replace the Transmission Control Module and it will work. Given that this dealership is not Mazda, I am very reluctant to be handing over more cash I don't have, and then the problem might still occur. Please, I beg you!, did you ever get it fixed? Thanks so much

 

i too am experiencing the same thing. driving along at speed and AT light flashes and car throws itself in third, light goes back out and car returns to normal. threw a u0101 code once but most times CEL doesnt even come on. my local trans shop swears its electrical and not mechanical, but having trouble finding cause of lose of communication with the transmission control module. checked connectors and pins, etc. problem not happening as often but still happening none the less. any info would be greatly appreciated. he doesnt think its the tcm but i guess thats still possible. hit me up on here or twitter @pilkyd getting desparate, alot of people have hard shifting etc, mine seems to be perfectly fine other than the split second episodes and then returns to normal for twenty, fifty, sometimes one hundred miles between??????

 

I have my Mazda in the dealership at the moment. They are currently checking all the connections, as the TCM is SUPER pricey, and I would rather check other options first. I'll keep you updated, but I would still like to know what happened with yours Ryan ....

 

Mine wound up being the TCM. The wiggled wires for like two weeks and I finally got them to replace it under my extended warranty. It would have been like $600 for tge part otherwise. It fixed it. Sorry for the expensive news. Everything else I saw was just dealerships waiting time until they replaced the part.