Sudden automatic braking issue (merged, MG4)

[Deleted member 10410]

I’ve learnt you can’t get in the car and rush off like an ICE car as an EV seems to need a gentle wake up period of a few seconds or a get flashing warnings until it all settles again.

However still 10 x better than my last car so still over the moon with my little MG4

 

[OJEastwood]

We have had several emergency stops and the alarm going off for no apparent reason.

My daughter in the back smashed her nose on the front passenger seat even though she was wearing seat belt

She shouted dad why did you do that, I said I didn’t the car just stops abruptly for no reason

What's worrying there is that your daughter's seatbelt didn't pull tight in an emergency braking situation

 

[aitch]

It shouldn’t pull tight, it should just lock after a set speed of belt movement.
it will only tighten through impact as it’s the collision sensors that cause the belt to tighten.

 

[OJEastwood]

It shouldn’t pull tight, it should just lock after a set speed of belt movement.
it will only tighten through impact as it’s the collision sensors that cause the belt to tighten.

I think I meant lock rather than tighten. I would have thought it should have done so in this scenario. If there’s enough velocity change to throw a person forward like that, then surely the locking should engage?

 

[Rolfe]

I've known children who deliberately wore their seatbelts loose or in a wrong way, so it could be worth checking that the girl isn't doing anything like that.

My godson, when he was around ten, used to thread his seat belt under his arm. I have no idea why his parents let him do it. If he'd been in my car that would have been stopped for sure.

 

[tsedge]

We have yet to have AEB activate the brakes (done 1,900 miles so far). So we leave it on.

What I have had is the warning beeps that it is going to take action, had that a few times when closing rapidly on someone else.

I am wondering if this is another area of having the right module updates, or maybe we have just been lucky.

 

[MoDolph]

What I have had is the warning beeps that it is going to take action, had that a few times when closing rapidly on someone else.

That's all we had had up until the weekend. It was also at times where I could understand why it thought there might be a problem, such as heading directly towards a car waiting at the temporary traffic lights of a contraflow.

 

[Rolfe]

We have yet to have AEB activate the brakes (done 1,900 miles so far). So we leave it on.

What I have had is the warning beeps that it is going to take action, had that a few times when closing rapidly on someone else.

I am wondering if this is another area of having the right module updates, or maybe we have just been lucky.

Actually, it's possible that all I had were the warning beeps. I can't remember if the car braked on its own, as I was braking or about to brake myself anyway.

 

[bowfer]

In VAG and Nissan cars I’ve had ghost ‘warnings’ where it beeps and/or gives a wee jab of the brakes to make sure you’ve noticed.
I’ve had audible only warnings in my Born too.
But I’ve never had any car do a full emergency stop. ?

 

[MG4London]

Mine is a warning beep and suddenly emergency stop.

It makes everyone in the car swear and blame the driver

 

[bowfer]

Mine is a warning beep and suddenly emergency stop.

It makes everyone in the car swear and blame the driver

That’s too extreme
Nissan and VAG are

1. Audible warning that you’re maybe coming up behind something too fast
2. If no steering or pedal inputs it then does a quick and sharp dab of the brakes to ‘wake you up’
3. If still no steering or pedal inputs, it assumes you’re asleep or dead and takes over.

 

[TomLane]

Driving out of a Morrison's supermarket at the weekend my MG4 suddenly decided to [for the want of a better phrase] emergency brake. This happened once before in the new year, but I out it down to a one off. Fortunately there was no one behind me, but it did give my passenger and I quite a shock. It was at an exit point with a street bollard nearby. I wonder if somehow the cars system my have mistook the bollard for a pedestrian, and if anyone else has had this problem/reported to a dealer? Once I've had feedback I can then discuss with my dealer. I'd appreciate any feedback from anyone else who have had this happen to them.

Hi, the system is setup for movement within a set area and certain shapes in the front and rear cameras. Unfortunately this is far from fool proof yet but is improving, my MG4 would not let me reverse as people were moving around behind me (not behind the car lol) I ended up going a little bit at a time, a very small bit but got out eventually. When I spoke with MG they said basically better safe than sorry???
Reduce the sensitivity or turn it off but it is a good feature when working right.
I hope this helps that you are not alone.
Tom

 

[TomLane]

That’s too extreme
Nissan and VAG are

1. Audible warning that you’re maybe coming up behind something too fast
2. If no steering or pedal inputs it then does a quick and sharp dab of the brakes to ‘wake you up’
3. If still no steering or pedal inputs, it assumes you’re asleep or dead and takes over.

Too extreme yes unless a child has run in front of the car or some idiot has pulled out in front of you, sorry bowfer I would rather have a few false alarms that have accidents. My MG4 sounds an alarm unless there is not time for the driver to react in which case it takes over. I think "too extreme" maybe a little harsh on the cars but maybe it does need some fine adjustments.

 

[MG4London]

I think my car is faulty

One time a motorcycle was approaching from the left and stopped at a junction as we were driving past normally at a safe speed and our car decided to do an emergency stop right in front of him!!!!!!

There was no reason to stop there and we almost get rammed from the traffic behind it’s a good job there was no cars immediately behind even at a safe distance they could have rammed us.

The biker wondered what on earth we were doing

 

[MoDolph]

I think the blame rests with NCAP. They simply don't test the systems well enough before dishing out the points. What good is a safety system that we all switch off?

How many times would you give a lift to a relative if they randomly pulled the handbrake or snatched at the wheel because they thought they saw something that wasn't there?

 

[CarlMG4]

I’ve learnt you can’t get in the car and rush off like an ICE car as an EV seems to need a gentle wake up period of a few seconds or a get flashing warnings until it all settles again.

However still 10 x better than my last car so still over the moon with my little MG4

I don't get this in my trophy at all, I often jump in and go, with no waiting around. Just enough time to put the Seatbelt on and I pull away.

 

[Buster72]

But saying that it also saved me (bit dramatic but still) when I was coming into left lane, looking over left to double check and car in front slammed brakes on. Luckily mine automatically stopped so it has its uses

Agreed. I was not trying to be critical of the system. It is, on balance beneficial.

 

[TomLane]

I think my car is faulty

One time a motorcycle was approaching from the left and stopped at a junction as we were driving past normally at a safe speed and our car decided to do an emergency stop right in front of him!!!!!!

There was no reason to stop there and we almost get rammed from the traffic behind it’s a good job there was no cars immediately behind even at a safe distance they could have rammed us.

The biker wondered what on earth we were doing

Please see my reply to the post above yours, I think you will find the car "thought" the motorcycle could not or would not stop in time and thinking it was too close for comfort did the "safest thing" and not hit him.
As for the cars behind, lets be totally honest they should not be traveling that close they cannot stop which is not your fault or that of the car.
My MG4 sounds a warning alarm unless there is not time for the driver to react - in which case it takes over the braking. I think "faulty" maybe a little harsh on the cars but maybe it does need some fine adjustments.

 

[bowfer]

Too extreme yes unless a child has run in front of the car or some idiot has pulled out in front of you, sorry bowfer I would rather have a few false alarms that have accidents. My MG4 sounds an alarm unless there is not time for the drive to react in which case it takes over. I think "too extreme" maybe a little harsh on the cars but maybe it does need some fine adjustments.

I think you’re overestimating the time frames, perhaps thinking the Nissan/VAG systems would take an age to slam the brakes on.
I’m sure that’s not the case, I’m pretty confident their systems are better than MG.

 

[TomLane]

I think you’re overestimating the time frames, perhaps thinking the Nissan/VAG systems would take an age to slam the brakes on.
I’m sure that’s not the case, I’m pretty confident their systems are better than MG.

Maybe, I don't know I was not in the car so cannot say but mine gets a little too excited even when coming up behind someone who is breaking but I suppose better safe than sorry but it is quite alarming.