Merged thread: Automatic Emergency Braking activating for no reason

Deakin

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Location
Stratford upon Avon
Driving
MG4 Trophy LR
My wife was scared sh**less this morning when her MG4 Trophy did a sudden and totally inappropriate emergency stop, whilst travelling at 30mph through a quiet nearby village. A Tesla was following at a safe distance and fortunately no collision took place. The car was then ok to drive away.
There were no nearby pedestrians or obstructions that could have confused to car systems. This has been reported to the dealership (Paul Rigby at Redditch) and I am awaiting a response.
We also have ongoing issues with the infotainment screen going blank or skipping from side to side, the radio and car play intermittently not working and also very unpleasant hypersensitivity of the lane depart functions. The dealer says there are known issues which MG do not have a fix for. Last week I was told that the earliest date the dealer could look at the car was 14/8/23! But if there is no software fix, then what’s the point of taking the car in?
We have also had problems with the charging, which sometimes goes to 100% when set to 80%.
Our confidence in this MG is fading and the dealership has been less than helpful.

The lasted emergency stop issue is downright dangerous. I await a response from the dealer on this, but it may be difficult to persuade my wife to drive it again!
 
There's a very relevant thread on this here.


The bottom line seems to be that some cars rarely if ever do this, and some are distinctly prone to it. Possibly needs something recalibrating, but it's very understandable that drivers lose confidence in the car once it has done this for no apparent reason. (The member whose car did it on the level crossing got rid of the car because his wife's nerves were in tatters.)
 
Having followed the other thread, I think it may be an issue with a camera or other sensor needing to be recalibrated. I hope they can fix this for you.

My car has done it twice, but both times there was a reason. The first time I was driving in traffic along Keighley Main Street, with a row of parked cars on my left. The car suddenly slammed on the brakes with no warning, but because my speed was low I wasn't in any danger of whiplash or anything. What had happened was that a man had come through between two parked cars, stepped out into the road, and opened the driver's door of one of the parked cars, right in front of me. There was in fact enough room for me to pass, if there had been no AEB nothing would have happened, but at least there was a reason for the stop.

The second time was when I was coming up behind a car stopped at road-works. The car obviously thought I wasn't braking in time, and the AEB came on absolutely simultaneously with me braking myself. I only realised what had happened because the force of the braking was harder than I had applied the brake pedal. Again, an obvious reason, and no harm done.

I've also had a beep-beep audible warning a handful of times, usually when I've been coming up behind a parked car and delaying pulling out because of another car coming in the opposite direction, but also at least once when coming up behind a stationary car signalling right. But that's no big deal, the brakes didn't come on.

You were lucky it was a Tesla following you. You were in no danger of being rear-ended. Twitter link to video (hope it works).



The Tesla AEB seems to be the only one that really works. Not that they haven't had their phantom braking problems too; one stopped suddenly in the middle of the new Queensferry Crossing bridge right under the noses of the CCTV cameras, and the clip was still being laughed at on the net weeks later. But Tesla seem to have ironed out the problems.
 
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Thanks for your response.

There does seem to be a number of clitches in the MG4 which they need to urgently address if the company is to avoid reputational damage.

Graham
There are a number and they seem to sort them eventually, the locking people in being one.

I genuinely don't believe they give a toss about reputational damage, MG UK customer service is hopeless.
Any customer service that take the stance off "talk to the dealer, it's nothing to do with us, we just sell them the car" tells you all you need to know.
The biggest thing with MG seems to be do your research and find a good dealer.
 
I usually always turn AEB off but don't bother for short journeys. Happened to me a couple of times needlessly. Last time I was only doing about 5-10mph and left me and passenger stunned for a few seconds having been thrown forward in seat belts before realising what happened and then having to quickly manoeuvre car our of way of other traffic to compose ourselves. Only thing that will make MG do anything about is is a big claim for whiplash. All this driver assist stuff is a load of nonsense. If a driver needs it then they shouldn't be driving.
 
Happened to me this morning, overtaking an HGV then the brakes went off. Will speak to the dealership about getting this sorted, IT IS DANGEROUS!!!
 
After having seen that video of all these AEB-equipped cars (except the Tesla) ploughing into cyclists and pedestrians regardless, including the MG4, I'm wondering if it's worth leaving it on. It hasn't gone off with me for no reason, and my feeling was that if it was potentially capable of preventing an accident then I'd leave it on, but if it can't even do that, what's the point?
 
After having seen that video of all these AEB-equipped cars (except the Tesla) ploughing into cyclists and pedestrians regardless, including the MG4, I'm wondering if it's worth leaving it on. It hasn't gone off with me for no reason, and my feeling was that if it was potentially capable of preventing an accident then I'd leave it on, but if it can't even do that, what's the point?
I posted the full NCAP video in response to the cherrypicked one, which showed that the MG4's AEB did work in most of the scenarios tested. Hence why it got the score it did. Of course it's up to the individual whether the frequency and potential danger of false positives outweighs the potential (very rare, but potentially life-saving) benefit of the system activating correctly.
 
I think I missed that link - do you still have it handy? I'd like to see it.

I don't mind leaving it on if there is a possibility that it might prevent a serious injury. So far the two activations I've experienced have been explicable. The number of people reporting unprovoked activation is a bit worrying, but of course when that happens people tend to come here to complain about it, understandably, so it won't be a representative sample.
 
Thanks very much.

Having watched that, it's quite reassuring. It does work quite a lot of the time. I'll keep mine on unless it starts behaving badly, which it hasn't as yet.
 
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Mine only seems to misbehave when I have ACC active. 🤷‍♂️ (As in - when I don't have ACC active I can't recall AEB ever operating; I've only noticed it when ACC has been active).
 
Just wanted to share and ask if anyone can offer any advice.

It’s happened twice now since I’ve had the car but this time was more of an issue.
Driving at about 35 when the car slammed on the brakes. No car in front (or behind luckily) but I can only put it down to a pedestrian on the edge of the kerb but I wasn’t near enough to be a reason.

Anyone else experienced this? Are there any ways to minimise the chances it happening again? If someone was behind me too close it would have been a rear end shunt without a doubt
 
This is a well known issue have a look a few pages back there is quite a lengthy thread on this
 
 
 
I had this but only at low speeds on about 3 occasions with aggressive braking for no reason. I took it to my dealer and one of the tech guys came out off his lunch break and looked at the car. He said he has had reports of this and went into the informant system and with a service code turned down the sensitivity. Ive just returned from wales over a 1000 mile round trip and its been flawless no issues at all and no warnings like i did get previously.
The cars going in next week for some ECU updates as i mentioned about the digital key and phone connection so fingers crossed. The tech guy did mention he thought there was an update for the radar situation and they were also going to make sure it was all aligned correctly.
Must say my dealer bends over backwards to help probably why there are 6 MG4s in a town with under 8 thousand people considering on my journey to wales i spotted one other.
 

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