2015 Mazda CX-5 Transmission Problem

[ALafya]

http://www.caranddriver.com/features/how-to-deal-with-unintended-acceleration

The claim is that even at full throttle the engine will easily succumb to full brake application with stopping distance barely being affected.
However, if you were not applying full stopping power, at least initially, I can see how this could be scary that you needed to fight the vehicle to make it stop.

I don't know much about what modern engines log, but I assume it is only if they had detected something unusual. But what if the system did not think something is unusual because it does not check for it or the check is incorrect. Now that they reset the computer there is better chances that any residual clue is now gone. Now, try proving you have no sister.

 

[BillofMass]

I like how anytime someone posts an issue a certain 2, maybe 3 members jump in and immediately challenge the posters integrity (i.e no respect) as if our cars have proven to be infallible. Or post a "it didn't happen to my car/never heard of it so it must be false" statement.

In order to insult anyone, they must first value your opinion. Nice try though.

 

[Chris_Top_Her]

In order to insult anyone, they must first value your opinion. Nice try though.

What exactly is that referring to? Did you google that?

 

[kralac]

I was not hard on the breaks at first but the more I realized something was wrong the harder I got on them and they did stop the vehicle and killed the engine. The problem is by the time the problem was identified I was running short in stopping area.

 

[kralac]

Thanks Chris. It's bad that trolls in forums cause so much distrust in people but I do understand people's leariness.

 

[outpost22]

It sounds to me like the transmission torque converter was locked up and wouldn't unlock when you decelerated. You might call or stop by a reputable independent transmission shop and ask their opinion. It may answer some of your questions.

 

[GAXIBM]

I agree that it sounds like the torque converter did not unlock as you decelerated which it should do in D or M as you can not normally kill the engine with the brakes only.

 

[iced_theater]

Don't know what your problem was, but your brakes should of stopped you easily. I decided to try out my brakes last night on my manual CX-5, and even in first gear at 4k rpm with the throttle to the floor the brakes stopped the car very easily.

 

[kralac]

I totally agree Iced that the brakes can stop the CX-5 very easily. The issue for me was that I wasn't using full force on the brakes and then noticed the problem but wasn't sure what was going on and finally had to lock up the brakes and they did work to stop the vehicle. But when you only have a few seconds to figure out what is going on you may be 1 second to late. 1 second to late can be the difference between life and death.

I agree with yall about the torque converter and I actually told both shops that it felt like that was what happened but neither of them have seemed to listen to that fact.


The latest news: Mazda called me today and wants to put a data recorder on my CX-5 and then let me drive it for several weeks to see if the problem happens again. I'm not sure how much I like this as I feel a bit like a guinea pig.

 

[dragonteeth]

The latest news: Mazda called me today and wants to put a data recorder on my CX-5 and then let me drive it for several weeks to see if the problem happens again. I'm not sure how much I like this as I feel a bit like a guinea pig.

Eh... Better than them shrugging their shoulders, I think.

 

[erhayes]

Good for Mazda. They are doing something positive to see if there is an issue or not. I'd be pleased with them. ed

 

[MikeM.]

Good for Mazda. They are doing something positive to see if there is an issue or not. I'd be pleased with them. ed

Agreed. It's about all they can do with such an odd, one off, report such as this.

I guess they could say something to the effect that there is no evidence of any problem and it's likely driver error but that wouldn't create any goodwill with the customer who believes there was no driver error. So, yes, they are doing the right thing.

 

[mz3_driver]

Someone suggested torque converter, but even if it doesn't disconnect, it's not hard to break a car that's pulling forward at 1,000 RPMs.

Maybe your engine died and your brake pedal had no boost? I know you said the tach showed 1K but could also be some electric issue... Just another theory.

 

[iced_theater]

Could the car of already been dead before you started braking? I'm wondering if you had no power brakes and that's why it wasn't easy to stop.

 

[GAXIBM]

Even if the engine died there should be enough vacuum capacity in the brake booster to assist stopping several times.

 

[mazdadude]

Any chance it was raining that day or perhaps you had just gotten a car wash?

 

[kralac]

Any chance it was raining that day or perhaps you had just gotten a car wash?

Nope it was a clear day. I had driven about 4 miles when it happened.

 

[V8toilet]

If in fact he is telling the truth than I would say it is possible that the transmission was in a higher gear like 4th (1-1 ratio I believe) gear and he lost vacuum boost for the brakes because the engine was at WOT or very low RPM and the reserve in the booster was used up. The Skyactiv transmission does use wet clutches above 5 mph so his description of it feeling like a manual is correct. It is possible, but unlikely, that the transmission got stuck in a gear especially with a brand new and tight unproven unit. It is possible that with the engine at WOT or at such low RPM that the engine wasn't producing enough vacuum for the brake booster to give him the impression that the brakes weren't stopping well enough especially if he doesn't have or didn't have enough leg strength. For these sequence of events to all happen at the same time is probably like winning the lottery but it is plausible. Knowing this though I would say even if your transmission does act up again that it's very unlikely that your brakes won't easily overpower the engine even if the engine was at max power.

If for some reason this condition did happen again (almost impossible) than all you need to do is mash the brakes and or bump the shift lever to neutral.

 

[Kedis82ZE8]

I may need to upgrade my physical OBDII readers to do live data... although that might be a moot point if the current reader I have for my iPhone will already do it. I have not sees a Check Engine light or drivability issue in a while so haven't looked into it much

 

[Raylance]

Any update to this post? Did mazda figure out what happened? I am considering a c
x 5.