DSC TCS failure multiple times....car left dead on the side of the road (almost)

[begwi]

Hello. I have a 2013 European diesel Mazda 5 with a 6 speed transmission and about 38,000 kms. While driving on the dry highway today, the DSC/TCS warning light came on with the transmission warning light. The car started to shudder, wouldn't accelerate, and the engine was slightly sputtering. I pulled over to the side and stopped, obviously. There were no leaks or burning smells from the transmission and everything else seemed okay. I started it up again and tried to drive, but the lights were still on and the car was not letting me accelerate; it would only shudder and barely move. Eventually, the lights went out and I started moving again, only to have the same thing happen 4 more times about 10 minutes apart - all at highway speeds on a dry roadway with no other issues. The check engine light eventually came on. I was not able to toggle the TCS system off with the switch during these episodes.

There was still nothing obviously wrong with the car mechanicals. I think it must have been a DSC/TCS component failure - causing the car to think it was skidding, which enabled the braking system to intermittently activate. This is likely the cause of the car shuddering and not accelerating. There was no indication of an ABS component failure (no ABS light).

So, I disconnected the battery temporarily, hoping to clear the failure. It worked. I drove the car 350 kms home with the TCS switch off and the check engine light on. The car largely acted completely normally. Yes - I know I probably shouldn't have driven that far in those conditions, but everything here is closed on Sundays....and managing this issue in a foreign language without a computer would have been difficult.

Now the car still has a check engine light and I want to figure out what happened. I know from searches, that there are TCS/DSC issues in the past - but I wasn't aware of them leaving people on the side of the road like my car did today.

Before I take it to the dealership here - does anyone have experience with this kind of failure? I am assuming some kind of relay or module failure in the DSC/TCS system. I am not thinking it is an ABS wheel spin sensor, but I guess that could be the cause too.

Thank you in advance for reading this story and providing any advice you have.

 

[begwi]

Update from today:

The local dealer said they could get me in next Thursday, 10 days from now. I explained to him in French the story above. I think he agreed that it is a component of the TCS. The engine check light was out today when I started the car to check it.

 

[begwi]

Update from the dealership visit:
Ok. The dealership says they found a problem with one of the fuel injectors. Well, that makes sense because I did notice every once in a while after the failure what I now know was a misfiring cylinder. We're talking like 1 an hour.
But, the dealership told me that the bad fuel injector was also the cause of the TCS failure - I don't believe that at all. I do know that some TCS systems, when active, reduce the output of the motor by shutting off fuel flow to some of the injectors. I'm not sure if my Mazda 5 works that way or not. But - for it to work the opposite way makes no sense: a problem with a fuel injector causes the TCS system to bring the car to a stop?! Can anyone provide an opinion if that could possibly be correct?
Regardless, they are going to order the part and replace the injector under warranty - I'll take it. I'm not convinced I will never see the TCS failure again.
The car has been running flawlessly since my June 15th posting - no TCS problems or misfiring cylinders.

 

[Wishmaster]

Interesting... don't think I've come across any injector failures crossed with DSC/TCS systems warning lights on this forum before. You would think a failure like that should just trigger the check engine light... strange.

 

[begwi]

Follow up: six months later, I've had no further problems (Injectors or TCS). I guess the injector fixed it.