Faulty Transmission

2012 Mazda CX-9

This problem may be covered under warranty. Ask your Mazda dealer.

CarComplaints.com Seal Of This Might Hurt

CarComplaints.com Notes: The only area of real concern for 2012 Mazda CX-9 owners is the brake booster.

In 2014, Mazda extended the warranty on the 2007-2013 CX-9 brake booster to 7 years / 90,000 miles. However this extended warranty has expired for most CX-9 owners, so buyer beware.

This Mazda CX-9 brake booster failure isn't terrible in terms of repair cost — it "only" costs $550 average to fix. However it is a safety issue when the brake booster fails as it increases stopping distance. Owners have reported having to stomp on the brake pedal, & crashes/injuries have been reported due to this CX-9 brake booster defect.


really awful
Typical Repair Cost:
Average Mileage:
36,500 miles
Total Complaints:
2 complaints

Most Common Solutions:

  1. faulty tcm (1 reports)
  2. replace transmission (1 reports)
2012 Mazda CX-9 transmission problems

transmission problem

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2012 Mazda CX-9 Owner Comments

problem #2

Aug 092013

CX-9 Touring 3.7L V6

  • Automatic transmission
  • 40,000 miles


I had just returned from being stationed over seas and my family and I were looking for a family car for our newly grown family of a daughter and dog. My wife fell in love with a 2012 Mazda CX-9 and we purchased it in March of 2013 at approx 20,000 miles. We moved up towards the washington state area and at about 40,000 miles we started more frequently noticing a hard down shift from 5th to 4th and took it in and the first time the techs didn't detect it, and then the second time they did detect it and ran every test and diagnostic to figure it out but couldn't find the issue. The dealership sent it off to Mazda corporate who analyzed it and deemed the transmission in critical condition. a week passed and i called the dealership to find out what was going on and found out that our transmission that was on "critical" was on backorder. Upon some "gentle" urging, they finally got a transmission headed out our way and it was replaced.

Update from Jan 16, 2016: Once the new transmission was in, starting day 1, we noticed the same hard down shift and the same high rev between 3rd and 4th gear on the upshift as was noticed before. It went back to the dealership a couple of times to have them tell me it was "within normal operating parameters". after 25,000 miles having put the new transmission in, we were getting ready to move and so I had the transmission fluid flushed by the dealership, where i had them verify the status of the transmission and was given the same answer of "normal operating parameters" I moved across country with noticeable hard downshifts and revs and got settled in our new home. At 91,000 miles I was driving the car on a slight uphill and all of a sudden the car was doing 6500 rpm's in 4th and wouldn't shift and the AT light was on. I limped it home, called Mazda roadside assistance and verified the transmission was under warranty and once i did so, i had them tow it to the local dealership. The tech diagnosed it as a blown transmission and told me it wasn't under warranty. I argued with Mazda and finally got them to pay for the transmission and half of the labor costs. The transmission was replaced.

Update from Jan 16, 2016: I went down to the dealership to pay and pick up the vehicle only to be told by the tech who was working on it, that the new transmission still did not fix the shifting issue and that there was still problems. He wanted to call up to Mazda corporate as far as what to do next and wasn't willing to release it in that condition. This gave me great faith and trust in this tech and dealership, but not Mazda. My wife who wanted this car, now wants nothing to do with it and doesn't trust the vehicle. She wants out of it and now I've contacted Mazda corporate to work out a solution.

Update from Jan 20, 2016: They talked with Mazda tech on Monday, 18 January 2016 and Mazda tech told them to try to change the TCM which i was told in the past by mazda service managers had been flashed. I was told that this TCM in my vehicle wasn't flushable, another lie from the dealership, and that a new one would be ordered "under warranty" today, 20 January, 2016 i was contacted by the dealership and told that the TCM arrived late last night and the tech was installing it today and I would hear back from them later today. I also called mazda USA to complain about the issues going on and have yet to hear resolutions from either issue being handled.

Update from Jan 20, 2016: I heard back from the dealership that the TCM was installed and that the car was running great and no shifting issues, but haven't heard back from Mazda yet on what they intend on doing about the issue at hand.

Update from Jan 22, 2016: My wife picked up the Mazda CX-9 from the dealership. They say it is fixed and are offering us an extended warranty on the powertrain, and the normal warranty regarding the transmission. I have yet to drive the vehicle to my satisfaction of regarding the fact that the transmission is now repaired. They have stated that the transmission was failed by a defective TCM.

Update from Jan 24, 2016: Vehicle seems to be driving ok for the first time since we've owned the vehicle and finally seems to have been corrected. Mazda USA offered us a discount on our next Mazda, extend the warranty to 100,000 miles, paid the price of the transmission and 50% of the labor charge with the dealership as well as the TCM the Mazda CX-9 required. They did not however do as my wife wished and pay the vehicle off and take it off of our hands as she no longer trusts the vehicle or Mazda's customer service team. She and I are looking now to get out from under this vehicle as fast as we can as she no longer trusts the vehicle or the manufacturer.

The final issue was not the transmission, but the TCM that the prior dealership told us they flashed, however the current dealership informed us that the TCM was not flashable, and therefore had to be replaced. Once this piece was replaced it seems to have solved the shifting issue, for now. knock on wood.

- asulli2012, Waterbury, CT, US

problem #1

Oct 252012


  • Automatic transmission
  • 33,000 miles

While 11 months ago I was totally excited to have a highly loaded 2012 Mazda CX-9, however, the SUV has so many annoying problems and serious problems that it would take pages to explain. For this complaint, the vehicle at 33,000 miles started having transmission slipping problems. I knew instantly that this was another example of poor quality. Now, we all understand that every vehicle can have issues but what happened at my dealer was a prime example of why leadership causes lost business in the long term. So, knowing that my car was screwed up and needed other repairs (window constantly screwing up and back hatch failures) they decided to give me a courtesy car while they checked out the transmission. Remember, this is not an expensive vehicle and is at the top of the Mazda line so what would you think they would give me? Exactly, a Chrysler 200. I was going out of town for business so could not argue so I took it hoping that in 3 days I would find out good news.

About 3 days later I found out that the transmission was rubbish and needed replaced. I asked WHEN would it be fixed. No answers, no clue, no facts. The news was that they had to ship it on the BOAT from Japan to the USA and then get it installed. At about the 12 day mark I had lost patience and kindness and demanded better service. I emailed the "Customer Assistance" and still had no answers. So, I went in to the dealer after work (a drive that is not close) to talk face to face with the service engineer (who is a solid person). Turns out that they magically have allowed for me to have an upgraded loaner over $30 a day. Wow, how nice. Anyway, I got a minivan and at the 35 day mark (+/- 1 day) my car finally had a transmission in it.

It is all about service and this dealer failed at a level that defies logic (besides being cheap). This is a TOP of the LINE Vehicle from Mazda and I am 100% sure if I would have bought an Audi, Cadillac, Benz, BMW, or about any car that the dealers would give me a loaner that was in the same playing field.

My best line and please feel free to use it (I told My Salesman that convinced me into Mazda Quality): "If this dealership sold $30,000 Beds and it broke you would make me bring it in and then give me an Oak Board to sleep on".....It is funny and the truth.

I feel that I had nobody to call above my dealership and here is the next part of the story. I have drove this newly installed transmission for two days now and it is shifting like a rock truck and it is an automatic. It was good to try out this morning while it was cold and it showed all the beginnings of being another junk transmission. You should not be jolted by every shift in a 6 speed automatic. When I first took ownership 12 months ago now the transmission shifted as expected.

For those that keep looking on line for a complaint about 2012 Mazda Transmissions and can't find any, I have no idea how that is possible. I have a real gut feeling that these SUV's have some serious lemons out there. The problem is that I have to drive this vehicle with my family for years to come and I have ZERO trust it will not leave me stranded. I buy NEW and maintained this vehicle at the dealership from the start and what I have now is a WILD CARD that cost about $36,000.

That is the story and if anyone from Mazda wants to talk to me I would be more than happy to share the experience. It is all documented. I want to believe that this was simply a matter of Dealership Rules that are not customer centered. However, I am starting to wonder if this SUV will ever be right.

Update from Jan 31, 2013: Well, the story continues.After the first transmission failure the new transmission was replaced (35 day wait) this transmission failed about 2 weeks after the replacement. I took it in and after 28 days I finally received a call that they would have to order me another transmission. They put in a Transmission Module believing that there is no way that TWO transmission could be JUNK!! Guess what, they ordered a transmission. I spent hours on the phone with the dealer and they said that Mazda is NOW aware that their transmissions are failing in the field and that they would try to get me a transmission ASAP. So, at another 35 day plus wait I have the THIRD transmission in the car and NO CALLS from MAZDA. I asked for names and numbers but the dealer said that they could not give me numbers and promised to do something for me. Here is the kicker, they gave me my car last Friday and didn't even have the class to wash it after they drove it around to check it out. My next step will be to see what Mazda and the Dealership is going to do for me. Think about it, 70+ days in repair in 14 months of ownership. Here is the kicker, this third transmission that is suppose to be the latest and greatest still has the stupid shift down to 4th gear that everyone complains about. It is so pathetic and without a doubt the worst transmission on the market. What vehicle stays in 4th gear at 20 mph? Drive one of these SUV's and start midly breaking at 60 mph (6th gear) and wait until you feel the "jolt" into 4th gear and see if it stays there until 20 mph. It is one thing to shift down on a brake tap down a hill but shifting down on a snow covered road is a recipe for disaster.

I am giving the dealer and Mazda another 30 days to come up with something that is fair for the nightmare they have put me through.

- indianagolf, Noblesville, IN, US

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