HELP!!! 2007 Mazda3 AT Trans Problem
 

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
Attachment 9197

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.

Oh and they should credit you the bullsh1t work they did towards the TCM since that has been the real problem all along. Good mechanics get paid good rates to fix it the first time!!!!

Thanks so much Ryan. Have you had any faults since? The dealership is checking the connections first. Because I'm in Australia, everything costs SO much more :( But this has really helped me. I watched your video, and was glad that someone else has experienced it aswell. I had a hard time just trying to explain the issue to the dealership.

hear anything yet, mine is parked until i hear more. ryan, did tcm cure all problems and if so how long has it been?

Mines still at the dealership. they want to hold it for a while to see if it faults again. They said they cleaned and tested all the connections. I dont think I want it back to be honest :'( And I love my Mazda, but it would break my heart if it happened again

mine is still parked, would love to hear an update!!

mine is still at the dealership. I went in there today to speak with the Service Manager, who appeared clueless when I asked why my car has been in there for 6 weeks. He obviously grilled the service rep. They are still clueless as to why it's doing what it's doing. I went in last week to have a look at the car, and it was in pieces. All I can say is, these "mechanics" at these dealerships are nothing but component fitters!

thanks
 

Just let me know please, i am gonna get a tcm soon, if that is what your problem ends up being than i'll feel better about spending the cash. Good luck

well friday i replaced the tcm with one i purcased online from salvage yard in NH. i have put 280 miles on it with no faults. longest it ever went before fix was 100 so i am optimistic that it was the tcm. used tcm was only 95 dollars with shipping compared to $680 from dealership. not too hard to replace, just remove battery and battery box, then metal bracket(two nuts) and its right there. take off wire harness and three bolts and swap. no programming needed. make sure the one you find ends in the same letter as the old one. i first heard that any from 07 - 09 would work, but others said no. to be safe i found one from same year and ended in same letter!

Well the dealership have washed their hands of it now. They dont want to have it back and they say that the wiring harness must be replaced at $5,500.00!!! I'm in Australia, and I find this ridiculous! The TCM was gonna cost me $1,760.00! So I have my car back ..... it's still not working. All the "mechanics" at the dealership no longer want to work on it, so two months on, I have my car back, in a far worse condition then when it went in, an emptier pocket, and no idea on what to do next. I can't even drive it, it's that bad! It shudders and clunks something chronic. It wasn't doing that before. It was just cutting out. The dealership that had it said that there was a backlog on the wiring harness and they are in such high demand! SERIOUSLY! If it's that much of a common fault: 1. why have you had it for 2 months? 2. Surely Mazda would have re-called the car? 3. YOU DON'T KNOW WHAT YOU ARE TALKING ABOUT BECAUSE YOUR COMPANY IS CLEARLY INCOMPETENT! I am so frustrated from all this. I want to change the TCM, but I have a feeling it's not that, because when the tow truck picked it up, there was transmission fluid all over the road. It was dripping out like a really bad bathroom tap! I figured I must have hit something and cracked a bolt or whatever. But I'm not stupid, and I'm almost 100% sure, I would have noticed a loud bang had I hit something. What were the excuses you were given before you decided on the TCM?

Sama Issue
 

I have the same problem: Mazda 3 2007 HB, 85K AT light on, CEL on, Changed oil, code say it was a transmission speed sensor, then changed sensor A and B. Someone told me it was the harness. Finally I decide to go to the dealer, they said they have to replace the computer, labor and parts around 1k. Then they said if this wont fix it I have to replace the tranny, around 3K. Really weird, just a problem with a sensor became a transmission replacement? Any one have the same problem? does it worth it?

I've just come from my meeting with the dealership regarding my SP23, to no success. They insist it's the wiring harness that produces the fault. From everything that you've all said, it's got to be the TCM. Because of all their "testing", the wiring harness is ACTUALLY broken now, and needs to be replaced regardless of the original fault ..... at my cost apparently. They did say they would pay to have the wiring harness spliced with a new connector at their cost, but if the problem persists, I must pay all extra costs. I've already forked out a ton of money to not have it fixed, and their incompetence will hit my pocket aswell it seems. So my beautiful SP23 is sitting on the verge at a friends house, rusting away because it can't be driven. I think it's about time Mazda stepped up and sorted out this fault. It's appears to be a common thing, so I believe the cars need to be recalled.

So the broken wiring harness has been replaced at the dealerships cost, thank god! But now they reckon it's the Main Computer that is making the transmission cut out. I was also told that I have to have a brand new TCM put in if I want it replaced, as a second hand one will not work. I'm so over it hey. It looks like I'm the guinea pig of Australian Mazda's with this one :(

Pilkyd, how's your TCM going?

about dealers.
 

i would rather suggest to look for outside mechanic coz when you bring your car in any dealers or any car service they will try to fix your problem but they will look more problems of your car and let you spend more money.. i have the same problem too, CEL and AT problem but accdg to what i research on mostly mazda 3 cars are only electrical problem that cause this malfunction or the TRANSMISSION CONTROL MODULE.. no need to rebuild your transmission or did anything more than you are asking to fix coz it will all end up on the TCM problem....

Well I've replaced my TCm at a cost of $1880.00 and it works just fine now. Mazda are useless and so are all car dealerships. They asked me why I wanted to replace the TCM, and I told them to just do it. They still thought it was a wiring harness problem even after I explained all the details that I've read off this site. USELESS!!! I thank everyone for their help, much appreciated.:)

I have same problem on my 2006 mazda 3. I am very close to buying the new TCM but I also would love to hear if after all this time the problem is still solved.

Also, someone mentioned about RPM-s jumping when in 5th gear. What is it? Is is override (6th gear) or a problem?

Since changing the TCM, I have had not a single issue since. It worked

Hi kristel

I just happend the same issue recenlty with my mazda 2010 and is been in dealership for 2months waiting for the parts import from japan. It happend with the fault code of U0101. Tried to solve with all kinds of way but now decided to replace TCM and i hope this will solve and get back my baby.

Im having the same issue with my mazda 3 2.3L 2008. I changed the front passenger mount cause the old ones rubber was literally sliced in half. Also changed the transmission fluid. The car still jerks on reverse. When I drove it for 1 block, it never passed 2000 rpm. I cant see what gear its it on the dashboard. Do i just need to replace the tcm or also the shift solenoids? Please let me know.

I had my TCM replaced on my 2010 mazda 3 2.0
 

Hey guys,i had a 2010 mazda 3 2.0 5 D with 106000km. I had the same occurrence on monday. I was driving 100km/h highway,all the sudden, I lost the speed down to 80km/h.I believed that the gear must have shifted down. It felt like I hit something.The AT light poped up and disappeared. The next time I started the engine, the CEL and AT light both poped up. I only could drive under 3rd gear. Eventually,I had to call a tow truck to a dealer. The dealer had it check with the scanner. The diagnosis of the u0101 error code was found. The mechanic suggested to replace the TCM, so I did. It worked so far with 10km drive. I haven't try it on the highway yet.I just can't understand based on my car mileage,what would be the cause of the malfunction of tcm? It doesn't makw sense to me. Can the scanner detect the malfunction of the harness?That would be the different error code?

2007 Mazda 3 TCM
 

Hungbryan:

I have a 2007 Mazda 3s automatic (132k). What you describe is what is happening to me also. Driving at 70mph on the freeway and it feels like I hit something and the AT light blinks and then quickly goes out. I have taken it to 2 different Mazda dealerships and the computer is storing no codes for them to pull. All the threads from the pass makes me think it's the TCM so I wanted to check and see if your problem has happened since changing it?

TCM fixed
 

Hi,I got my brand new TCM replaced for a month. I have driven for almost 2000K both on highway and city.highway mostly.
The gear shifted alright,but I think the trany has re-learned. The timing of the gear shifting has changed compare to the past. It's not as smart as before. Maybe it needs more time to learn from my driving pattern.
Also, I noticed the sound of engine is greater. I am not so sure it's correlated with the damage of gearbox or not.
After all, the malfunction has fixed.

Glad you got it sorted out, bryan :bt:

Is it the same problem?
 

Hi Guys,

Newbie here. I have a 2008 Mazda AT 1.3.

Just wanted to ask if I have the same issue as this thread talks about, here are my 3 issues that are currently occurring to my m3.

1. When I'm at the highway, I'm running at 80km/h riding in 2000RPM under D-4th gear (4th gear is the max for my m3). When I tried slowing down and accelerating again, the RPM surges to 3000 to 4000RPM while the dropping into 2nd Gear. This symptom is quite new to me since I own the car since 2008.

2. When I'm in stop, I noticed that the rpm surges when I put it on Neutral or Park mode without stepping the gas. When I put it back on Drive mode, it becomes normal.

3. Shift lights (1, 2, 3, 4) sometimes goes of for 30 secs to 1 min. And it will just come back normally.

What could be the issue here? Thank you guys for all the support. It's been bothering me for months now, and I just recently joined this thread because it seems like i'm having the same difficulty with the same issue.

Hi All,

A similar scenario happened with my 2007 2.3 liter 3 with 126K miles on it back in November. Out of nowhere, the car dropped to 3rd gear on the freeway and wouldn't shift out. I got the car towed to the dealer and while I waited for the tow, I read similar stories on this forum and others about the transmission control module needing to be replaced.

As soon as I got to the dealer and drove it off the flat bed, the CEL and AT light went off. Of course! The service manager agreed to keep it for the day and put some miles on it to see what happened next. As soon as the moved it out of the garage the AT light came back on and the car got stuck in 3rd. They pulled the code (P0753 - shift solenoid). Based on their experience with this vintage, they were already pretty certain what needed to be done. After discussion, I agreed to have them re-program the TCM before replacing to see if they could bypass a software glitch. AT came back almost immediately. After authorizing replacement of the TCM, I've had the car back for 4 months and have had no problems.

Expensive, but, seems to have been the only way.

Side note - Consumer Reports ratings on used cars highlights that the 2007 had trouble spots in transmission (minor) and suspension. I've found this to be spot on.