Sudden automatic braking issue (merged, MG4)

JonnyG · Oct 27, 2024

NLMGSAN said:
.....Conclusion: they are both to blame.

Agreed and is what I said above is it not ?

"I agree that testing needs to improve and include proper road driving"

and also from NCAP :-

"Vehicle manufacturers have a responsibility to ensure that the vehicle performance seen on a test track is also reflected in on-road driving"

LenEV2016 · Oct 27, 2024

JonnyG said:
Agreed and is what I said above is it not ?

"I agree that testing needs to improve and include proper road driving"

and also from NCAP :-

"Vehicle manufacturers have a responsibility to ensure that the vehicle performance seen on a test track is also reflected in on-road driving"

I think you did

NLMGSAN · Oct 27, 2024

JonnyG said:
Agreed and is what I said above is it not ?

"I agree that testing needs to improve and include proper road driving"

and also from NCAP :-

"Vehicle manufacturers have a responsibility to ensure that the vehicle performance seen on a test track is also reflected in on-road driving"

True. I just used more words..

LenEV2016 · Oct 27, 2024

NLMGSAN said:
True. I just used more words..

Seems to be the way on this forum

AmperaE · Dec 10, 2024

Last saturday evening I was driving on a main road between Montrose and Arbroath. It was dark, very windy and wet. I was driving in adaptive cruise control (acc) mode and had automatic emergcy braking (AEB) on. The MG4 suddenly braked quite strongly but briefly on the approach of an oncoming vehicle (in its own lane, I think in a bend). There were no cars in front of me or behind me.
I then switched off the AEB, but the same thing happened again twice a bit later. I blame the ACC, but I'm not sure. It might be a matter of calibration or aligning the radar, or just the weather.

I had emergy stops in town a couple of times. Once I was in acc and there were a parked vehicles in my lane. Another time when I approached a parked vehicle too quicky. Both occasions were not OK, but I could see a point.
Uninvited braking at high speed (60 mph) is quite disconcerting.
Any thoughts ? Is there perhaps a software update on it's way that can switch off all the automated crap once and forever ? I wish I had kept my Ampera-E

Logan T · Dec 10, 2024

AmperaE said:
Last saturday evening I was driving on a main road between Montrose and Arbroath. It was dark, very windy and wet. I was driving in adaptive cruise control (acc) mode and had automatic emergcy braking (AEB) on. The MG4 suddenly braked quite strongly but briefly on the approach of an oncoming vehicle (in its own lane, I think in a bend). There were no cars in front of me or behind me.
I then switched off the AEB, but the same thing happened again twice a bit later. I blame the ACC, but I'm not sure. It might be a matter of calibration or aligning the radar, or just the weather.

I had emergy stops in town a couple of times. Once I was in acc and there were a parked vehicles in my lane. Another time when I approached a parked vehicle too quicky. Both occasions were not OK, but I could see a point.
Uninvited braking at high speed (60 mph) is quite disconcerting.
Any thoughts ? Is there perhaps a software update on it's way that can switch off all the automated crap once and forever ? I wish I had kept my Ampera-E

I've had AEB occur 3 times at speeds of below 5 mph since I had the car 20 months ago. All on bends or traffic approaching from the side. All were unpleasant and could have caused a rear collision.

If it occurred at 60 mph I'd be at the MG dealer the next day demanding action.

Cocijo · Dec 10, 2024

I know that it’s not really much of a consolation, but in my experience no car manufacturers have got this area completely nailed down.
I’ve mentioned before that Tesla, who many consider to be better than most at car software, still have issues in this area.
It’s an introduction of something that is not quite ready. Is it an 80/20 situation? Probably. At the moment I guess it can prevent incidents and save lives, but it can also cause them. Is it viewed as a trade off?
I’ve owned and driven quite a lot of new cars over the last few years - many with what are considered to be the best safety systems - e.g. Volvo, BMW,, Mercedes, Tesla. All of the cars that I have experience of have issues at certain times when it comes to areas like automatic braking and cruise control. They getting better but they have a way to go.

NLMGSAN · Dec 10, 2024

AmperaE said:
I then switched off the AEB, but the same thing happened again twice a bit later. I blame the ACC, but I'm not sure. It might be a matter of calibration or aligning the radar, or just the weather.

Join the club. It is ACC. Not the AEB system
I drove hundreds of miles without acc and with AEB. No issues. Then I reversed to no AEB but with ACC and the very first day it happened. The usual suspect was an 80 kmh crossroad with traffic lights. Me going straight ahead, traffic in the right lane leaving the road. That traffic is slow and while passing that traffic my car slams the brakes.
After informing the dealer they said they had an update of the calibration. This helped. However, now the car is scared if it gets 'tunneled'. Particularly large vehicles such as trucks to both the left and right scares the car. So it just slams the brakes. Bad weather doesn't help.

AmperaE · Dec 18, 2024

NLMGSAN said:
Join the club. It is ACC. Not the AEB system
I drove hundreds of miles without acc and with AEB. No issues. Then I reversed to no AEB but with ACC and the very first day it happened. The usual suspect was an 80 kmh crossroad with traffic lights. Me going straight ahead, traffic in the right lane leaving the road. That traffic is slow and while passing that traffic my car slams the brakes.
After informing the dealer they said they had an update of the calibration. This helped. However, now the car is scared if it gets 'tunneled'. Particularly large vehicles such as trucks to both the left and right scares the car. So it just slams the brakes. Bad weather doesn't help.

Thanks for the expanation. When I understand you correctly, you say leave AEB on but do not use ACC (except perhaps on motorways). And be careful with calibration, because it might get worse.

NLMGSAN · Dec 18, 2024

AmperaE said:
Thanks for the expanation. When I understand you correctly, you say leave AEB on but do not use ACC (except perhaps on motorways). And be careful with calibration, because it might get worse.

That would be my suggestion. Both radar and camera are not flawless, whether because calibration or obstruction issues. I have detected errors of the ACC system such as seeing 'ghost objects', or it interprets cars/vehicles that are actually to the right of you as if they are in front of you. AEB is activated based on such errors.

GoElectric · Dec 19, 2024

What is MG4 using as sensors for ACC?

If it is using also camera in the nose, the ghosts could (apart from code problems) appear also due to dirty lens cover or reflections from within the module.

What I mean by the latter is it maybe can happen that the camera module sees a reflection on the lens cover from within the module. Like for example you can see your eye/face in sunglasses under certain sun angle conditions. It would be interesting to test with an antireflection film on the inside of the lens cover.

When I notice this happening I usually immediately override by pressing throttle pedal. Luckily it very rarely happens.

NLMGSAN · Dec 19, 2024

It uses camera and radar.
If the camera lens is dirty, sudden braking would not be associated with e.g. parked cars to the side of you. It would happen everywhere and in any situation. But true, it does no help.
I have a video that shows at one point the sensors actually spot a motorcycle in the emergency lane when there was nothing but a steel barrier. Also, while overtaking a truck the system displays the truck to right, suddenly again in front of me (car drops in speed), and then the truck disappears to the right again.
Note that the manual warns for ineffectiveness of ACC in case of "Encounters a vehicle with a higher chassis (e.g. a truck)."

In other words, the ACC sensors and software are far from perfect.

ReintjeWA · Dec 19, 2024

I always wonder how the car knows (or thinks it knows) there is a car ahead of the car in front of me. Surely the radar nor the camera could see that, so it would be an estimated guess right? Or would the radar see the next car through the first car's windows maybe?

siteguru · Dec 19, 2024

The radar is low down in the bumper, so depending on road elevation/undulation it may "see" something ahead of the vehicle in front.

WonkoTheSaneUK · Dec 19, 2024

ReintjeWA said:
I always wonder how the car knows (or thinks it knows) there is a car ahead of the car in front of me. Surely the radar nor the camera could see that, so it would be an estimated guess right? Or would the radar see the next car through the first car's windows maybe?

The radar sensor is behind the coloured panel below the number plate and between the vent grilles.

markglawrence · Jan 22, 2025

[ Moderator: This is the start of a thread merged with this older but still active thread. Continuity may be affected in later posts. ]

New to this forum.
Has anybody else experienced this?
Driving on a quiet road, nothing in front and a few cars behind is.
The car suddenly brought us to a sudden stop for no reason that I could think of.

siteguru · Jan 22, 2025

Set the sensitivity for AEB (Automatic Emergency Braking) to Low. The system will have detected something, or thought it did, so brought you to a stop. Were you driving into a low sun?

chromeskull · Jan 22, 2025

Funnily enough this happened to me on Sunday in my MG4.
popped into the supermarket and the car park entrance next to the petrol station bends back on itself (180 left turn) as it splits off to either go to one side of the car park or the other.
About half way around the bend, I indicated right to go to the closest side of the car park, a car had emerged in the opposite direction I was heading for on it's side of the lane.
Literally as I crossed over the wight lines to turn into that entrance my car panicked and locked all 4 wheels. I was going less than 10mph at that point (sharpish corner) but this had put me dead of the road. A bit embarrassing trying to get the car to move again by dabbing the brakes and then the throttle to no joy. After a couple of seconds it allowed me to move off.
I assume my car thought the other car was heading towards me during its own turn.
See the attached image of the site. I emergency stopped at the red X, the other car was at the Yellow Arrow when it stopped.

markglawrence · Jan 22, 2025

Thanks all for your responses. It’s comforting to know that it’s not just me.
It’s a new car and my local dealer has said that it’s a safety issue and need to get the car to them.
My wife was driving at the time and we were both in shock after it happened.
I fear that if the garage doesn’t identify and correct an issue I don’t see my wife ever getting back in to it. Very shaken up.
IMHO it is not acceptable for cars to take over driving decisions like this. It was v fortunate not to have caused an accident. Much hooting and hand gestures caused, no actual contact though.

Everest · Jan 22, 2025

markglawrence said:
I don’t see my wife ever getting back in to it. Very shaken up.

I can totally understand that! These automated systems are simply not up to coping with real-life situations.

This is something I've been looking into before buying an MG4, but from what I have read it is possible to totally disable the emergency braking system before you drive the car (someone please correct me if that is not the case!). Though that has to be done on every journey which I can see will be a real nuisance.

Sudden automatic braking issue (merged, MG4)

Prominent Member

Established Member

Prominent Member

Established Member

Standard Member

Standard Member

Distinguished Member

Prominent Member

Standard Member

Prominent Member

Standard Member

Prominent Member

Established Member

Distinguished Member

Prominent Member

Standard Member

Distinguished Member

Established Member

Attachments

Standard Member

Established Member

Similar threads

Yes

I'm in the middle

No

Latest MG EVs video