Author Topic: Sudden unintended acceleration  (Read 1405 times)

Offline agj

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Sudden unintended acceleration
« on: April 04, 2019, 04:36:13 pm »
I recently had an accident with my new CX-5 2018 Automatic Petrol which I believe is a vehicle fault - Wondering if anyone has encountered this issue before?

My wife was parking the car slowly into a wide bay (parent and child one) at the local supermarket - As usual, she had her leg on the brake and slowly moved into the bay, but just as it was coming to a halt, the car suddenly accelerated forward and crashed into a parking barrier, smashing a front headlight, bonnet, etc. We have had the car for about 3 months and never observed any such issue. Very strangely, the car's parking / proximity sensors which are usually very good didn't go off at all and neither did the smart brake assist which would indicate a BRAKE!!! warning on the dash.

I have raised it to the dealer, but beyond doing a basic diagnostic test (which in opinion only indicates faults that the computer can see easily) and a quick road test, weren't interested in checking further - No investigation of EDR logs to confirm vehicle / driver fault, no check of sensors or the parts that could cause sudden acceleration issues to confirm all clear.

Has anyone encountered anything like this? Any ideas of how to take this up further with the dealer? It is not just the cost of repairing the damage, but also the worry that if the car does something like this again, with cars or people in front, it would be really terrible.

In most such cases, people tend to write this off as "accidental slip of leg to accelerator" or other driver error, but this is really not driver error. Other friends have also observed similar issues, but on other car makes. The Mazda CX-5 has similar reported issues of sudden unintended acceleration, but in the US.

Offline dunhill1984

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Re: Sudden unintended acceleration
« Reply #1 on: April 06, 2019, 12:51:52 am »
How can your wife have a foot on the brake in an AUTO when accelerating forward?  i suggest she pressed both pedals at once by accident and braked/moved forward at the same time..........and rather blame herself blamed the car instead to avoid a row ;)          just a possible theory
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Offline Mary Hinge

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Re: Sudden unintended acceleration
« Reply #2 on: April 06, 2019, 06:47:45 am »

Offline Willpower

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Re: Sudden unintended acceleration
« Reply #3 on: April 06, 2019, 08:35:03 am »
Does anyone else find it strange that the first two failure reports on the link above, have every indication that they were written by the same person.   Look at the words used, the language construction and phraseology. They are too similar to have been written by two individuals.

I'm not saying that there is possibly a inherent problem here, but my impression is that the reporting of it in the link is being exaggerated. This diminishes the validity of the report entirely.
   

Offline agj

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Re: Sudden unintended acceleration
« Reply #4 on: April 07, 2019, 07:22:47 pm »
@dunhill1984 - When you enter a parking bay with enough movement, you'd bring it to a halt by applying the brakes slowly and then finally braking fully. I understand your point - Sometimes (esp. when you need more power), you use accelerator to move within the bay and apply brakes at the very end. I understand the whole "sudden unintended acceleration" thing is quite unexpected and difficult to believe till you experience it yourself, and I frankly quizzed my wife many times initially :) She is a very safe driver, btw with a clean driving record and this was an easy to park bay, being a wide "parent and child" parking bay.

@Willpower - Yes, the failure reports look very strikingly similar. Infact, I read the first one when we were at the dealer's immediately after the accident, getting the car checked for faults. The similarity with what we encountered was very striking to be frank - Almost like this only happens in supermarkets and during parking! It is the similarity that further concerns me and convinced me that there is indeed a vehicle fault at play. There is an NHTSA complaint (DVSA equivalent in US) as well for this - I think we need to take the complaint as a serious one. No one would really bother with all this energy on raising NHTSA/DVSA complaints, etc. if they were simply trying to cover up driver error (Honestly, from experience, these conversations with the dealer and the company suck out all energy you have and I would have given up if not for the concern around risk and feeling of being treated unfairly just 3 months into ownership).

Mazda UK and my local dealer (Brayleys Harpenden) have conveyed they are "unable to find any faults that could cause the accident", but refuse to give me more evidence of what they have checked and also refuse to confirm if the vehicle is safe to drive - Really shocking considering I just bought the car from them 3 months ago! The dealer I bought the car from (about 50 miles away in Croydon) was initially all warm and ready to help, but as we got into the detail, said they would only do the same diagnostics as the local dealer and strangely said that "they can do more tests but cannot change the outcome". I would really have expected them to instill confidence in the customer by 1. doing a check of the EDR log to confirm how crash happened and 2. do a check of the parts that are likely to cause issues (starting with the oft-repeated 'loose mats', pedals, etc.) and confirm that the vehicle is safe and road-worthy. If they cannot do more, in my opinion, they are only passing on the risk to the customer, a bit like Boeing had just refused to acknowledge issues with its 737 Max planes, till fatal accidents occurred.

I am in the process of raising this with the Motor Ombudsman and the DVSA, but if you have any suggestions or additional evidence (other reported issues), that would greatly help.

Offline aljshep

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Re: Sudden unintended acceleration
« Reply #5 on: April 08, 2019, 09:09:39 pm »
This has happened to me TWICE.  I put it down to driver error.  I was driving a 2016 Mazda 6 (diesel auto) which has now been sold.

The first time I was stopping to park behind another car at slow speed.  About 6 feet from that car  the BRAKE warning deployed as I shot forward.  I lifted my right foot and slammed it on the brake pedal.  We stopped with an inch to spare.

The second time I was again driving slowly - into a “nose-in” parking space.   Again, the car jumped forward and the front wheels mounted the kerb.  Again,  I lifted my right foot and slammed it on the brake pedal and stopped without hitting anything.  No warning as there was no obstacle ahead.

I had assumed in each case that I had my foot lightly on the accelerator pedal and pressed it to slow.  Then pressed harder as the car sped up and then pressed even harder.  As I said – driver error.  But now I am not so sure!  I have been driving automatic cars for over 50 years and never had anything even remotely similar before.  On the other hand, there are numerous reports of elderly drivers braking sharply with the accelerator pedal and coming to grief.  I doubt that I will ever know.

Offline Anchorman

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Re: Sudden unintended acceleration
« Reply #6 on: April 09, 2019, 07:45:38 am »
I think mine did something strange one day which resulted in a collision but I’m not confident enough to say that it wasn’t my driving.  It felt very unusual.
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Offline Deeps

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Re: Sudden unintended acceleration
« Reply #7 on: April 10, 2019, 12:27:23 pm »
@dunhill1984 - When you enter a parking bay with enough movement, you'd bring it to a halt by applying the brakes slowly and then finally braking fully. I understand your point - Sometimes(esp. when you need more power), you use accelerator to move within the bay and apply brakes at the very end.

In all of the 50+ years that I have been driving, and especially since moving to automatic cars, I can't honestly recall a single occasion when I have needed to accelerate within a parking bay. The Mazda automatic box is of the type that when left in D will continuously creep meaning that one has to firmly apply the foot brake or move the stick into N to counter this. This creeping happens all the time and it doesn't matter whether the vehicle is pointing uphill, downhill or on the flat. In short, with gentle light-footed movement of the brake pedal there is enough of a creep to maneuver safely into a parking bay, or out of it when the stick is in the R position.

I agree with Willpower in that the first two posts in the above mentioned link appear to have been written by the same person and would perhaps go further by saying that if there was actually a design fault resulting in this sudden and unwanted acceleration I would have expected to have read/heard a lot more about it at this time. A design fault by definition is a design fault and would apply to more than just a handful of vehicles.
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Offline steve101

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Re: Sudden unintended acceleration
« Reply #8 on: April 11, 2019, 07:24:33 am »
I would have to agree with Deeps. The only time I have noticed a lack of creep is on a steep hill, upwards.

Offline dunhill1984

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Re: Sudden unintended acceleration
« Reply #9 on: April 12, 2019, 01:18:50 pm »
Very strangely, the car's parking / proximity sensors which are usually very good didn't go off at all and neither did the smart brake assist which would indicate a BRAKE!!! warning on the dash.


   smart brakes dont work at very low speeds(<2.5 mph)
« Last Edit: April 12, 2019, 01:21:05 pm by dunhill1984 »
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Offline agj

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Re: Sudden unintended acceleration
« Reply #10 on: April 27, 2019, 01:59:46 pm »
Thanks for the replies...

Design faults - Agree that if it was an evident design issue, it should manifest more commonly. But there are random occasional issues that are really hard to isolate. If you search for "sudden unintended acceleration", Toyota in the US had such instances but kept pushing it off as driver error till there were fatal accidents and the counts started to creep up. I work in software and understand the nature of 'software defects' - Some happen only very very occasionally and are hard to simulate, but are still a real risk.

I have raised this issue with the Ombudsman and DVSA - Waiting on a reply.

With regard to the CX-5, I noticed a strange behavior right after purchasing the car - When starting the car, the engine would race a bit for about 10-30 seconds before it settles down. Sometimes this would be after cold start, but not always - Even stopping the car after running for about 10min and then restarting would result in the 'racing'. The recovery vehicle driver also said this looked very strange. Has anyone noticed the same?

When I showed this to the dealer a couple of weeks after purchase, they had a mechanic drive the car and check - They said its normal for the CX-5

I haven't noticed this behavior on any other car - Mercedes, Hyundai, Ford or Vauxhall. They all just start and don't race (when idling), even for a cold start. With the CX-5, there is a perceptible 'racing' and rpm fluctuations, though in a small range.

Another weird one is the strange sound at lower gears, when accelerating - The CX-5 has a strange 'electric motor' type sound at these gears / quick acceleration which is again something I have never heard in any other car. This may be down to how the CX-5 Petrol Auto is, but just checking if that's not the case

At higher gears, though the CX-5 is really smooth and silent.

Offline dunhill1984

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Re: Sudden unintended acceleration
« Reply #11 on: April 28, 2019, 10:49:09 am »
Mine races as well-its normal for this non turbo skyactiv engine i have been told
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Offline agj

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Re: Sudden unintended acceleration
« Reply #12 on: April 30, 2019, 07:02:35 pm »
Thanks....that's good to know.

Did you find the noise at lower gears strange / different from other cars too?

It may be down to the fact that it is a non-turbo petrol.

Offline Anchorman

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Re: Sudden unintended acceleration
« Reply #13 on: April 30, 2019, 11:08:05 pm »
Thanks for the replies...

Design faults - Agree that if it was an evident design issue, it should manifest more commonly. But there are random occasional issues that are really hard to isolate. If you search for "sudden unintended acceleration", Toyota in the US had such instances but kept pushing it off as driver error till there were fatal accidents and the counts started to creep up. I work in software and understand the nature of 'software defects' - Some happen only very very occasionally and are hard to simulate, but are still a real risk.

I have raised this issue with the Ombudsman and DVSA - Waiting on a reply.

With regard to the CX-5, I noticed a strange behavior right after purchasing the car - When starting the car, the engine would race a bit for about 10-30 seconds before it settles down. Sometimes this would be after cold start, but not always - Even stopping the car after running for about 10min and then restarting would result in the 'racing'. The recovery vehicle driver also said this looked very strange. Has anyone noticed the same?

When I showed this to the dealer a couple of weeks after purchase, they had a mechanic drive the car and check - They said its normal for the CX-5

I haven't noticed this behavior on any other car - Mercedes, Hyundai, Ford or Vauxhall. They all just start and don't race (when idling), even for a cold start. With the CX-5, there is a perceptible 'racing' and rpm fluctuations, though in a small range.



What don’t you get?  You won’t notice it with other makes because they either have other ways of treating emissions or they don’t meet Euro 6.

The CX5 is DESIGNED to do it.  It isn’t an “issue” it is supposed to do it.

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Offline dunhill1984

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Re: Sudden unintended acceleration
« Reply #14 on: May 01, 2019, 12:00:28 pm »
HI agi,my previous cars were diesels so i cant compare but i got used to it after a few weeks
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Re: Sudden unintended acceleration
« Reply #14 on: May 01, 2019, 12:00:28 pm »