Merged thread: Automatic Emergency Braking activating for no reason

[Surfdog]

A couple of months ago I posted on this thread dashcam footage of my sudden emergency stop for no apparent reason. Its still up if you haven't seen it. I took the car back to the dealer who could find no issue. I subsequently sent the footage to MG UK. Here is their reply.

"Thank you for your email and the video which makes the scenario a little easier to explain. I am sorry that this feature is not meeting with your expectations.
At around 13 seconds, the red car (I think its fiat 500 turns into your road. The bend/camber of the road as the car turns in, means that the camera/radar has the red car in its direct line of sight and sees it as an obstacle that you are about to crash into.
When you advise there is no obvious hazard, this is the hazard that it is seeing.
I can only recommend turning the sensitivity of this feature down at the beginning of the journey."

Having experience of this appalling feature on the MG4 I do agree with the MG diagnosis of what caused the emergency stop. However, my footage clearly shows the system is deeply flawed and in fact dangerous. As you can see from the footage I was driving at a safe speed, in the middle of my lane and at a safe distance from the car in front. The car approaching me, that MG refers to was also driving at a safe speed and in the middle of the opposing lane and was not steering across the lane towards me. All vehicles in the footage were being driven in a safe manner on a normal UK road. There was absolutely nothing adverse about the situation.

So, in effect, MG are saying, be prepared for sudden emergency braking when a car is approaching you while negotiating a bend, even though a collision is not imminent. They appear to be happy that this is acceptable.

So I will be keeping this email and my dash cam footage should I ever be the victim of a rear end shunt where the offending driver attempts to blame me. Feel free to use this reply too if you ever have need to do so.

 

[hawleybeach]

One question about ACC slowing the car: does it happen when you overtake another car?

Not whilst overtaking. I only noticed the sudden slowing whilst rolling through Country Towns at 60kmh

BTW ... ACC works perfectly well on some vehicles. I drove a Hybrid RAV4 from Melbourne and Canberra and back a couple of years ago, and when I was coming up behind trucks on the Hume Highway I was wondering why I wasn't catching them anymore. The RAV4 had been able to slow down by about 10kmh without the passengers in the car even noticing

On the other hand, the MG4 would suddenly use regenerative braking, lose too much speed, than automatically accelerate again in similar circumstances

 

[NLMGSAN]

Thanks for the reply.

About that acceleration: you mean when you are in the next lane?
Cause mine simple loses speed even when I move the car into the next lane. Drops speed from 100 to 90 kmh, sometimes less. It happens in all distance mode, but only with trucks. My take is that once I get close to the minimum distance (at 2 sec and 100 kmh this is 55 mtrs), the car drops in speed. It keeps slowing down because trucks are big so the camera and radar still see the slower vehicle in front of me. It stops accelerates again when I'm pretty much starting to pass (free sight in front of the mg).

 

[hawleybeach]

Thanks for the reply.

About that acceleration: you mean when you are in the next lane?
Cause mine simple loses speed even when I move the car into the next lane. Drops speed from 100 to 90 kmh, sometimes less. It happens in all distance mode, but only with trucks. My take is that once I get close to the minimum distance (at 2 sec and 100 kmh this is 55 mtrs), the car drops in speed. It keeps slowing down because trucks are big so the camera and radar still see the slower vehicle in front of me. It stops accelerates again when I'm pretty much starting to pass (free sight in front of the mg).

By "Acceleration" I was just referring to the apparent lack of calibration of the ACC system. This was just following traffic in the same lane

 

[pjmmk]

I can only recommend turning the sensitivity of this feature down at the beginning of the journey."

Another thing to add to the ever growing list of things to set before driving the car. It's getting more and more like piloting a plane. I'm going to miss being able to just get in a car, hit the start button and go

 

[Surfdog]

Another thing to add to the ever growing list of things to set before driving the car. It's getting more and more like piloting a plane. I'm going to miss being able to just get in a car, hit the start button and go

Yea, i wasn't aware we could turn the sensitivity of this down. I can only assume that by moving the left steeeing wheel joy stick to the left does this for emergency braking. I thought this was only effective for ACC when adjusting the reaction distance from the vehicle in front.

 

[hawleybeach]

Just needed to add, if you have selected "Towing Mode", that doesn't automatically reset, you still get asked to confirm each time you start your car. The Options are "Cancel" and "Settings"

Settings - Will allow you to turn "Towing Mode" OFF

Cancel - Leaves it in "Towing Mode"

If you do want to use the Reversing Sensors or Cruise Control, you will have to go through the usual "Pre Flight Routine"

"Towing Mode" keeps all the automatic stuff turned OFF ... The car barely beeps, which is a bit weird if you are used to the usual constant beeping

 

[Logan T]

I’ve now had the LKA fix at my first service, and it is certainly a lot less sensitive and far less frequent in giving the jerk to the wheel. Does anyone know if the fix also improves the emergency braking sensitivity. Logically it should as I assume it’s the same camera?

A late reply...
I've had updates with improved the LKA sensitivity but have recently had 2 more spurious AEB incidents (luckily no one behind me).
So, it looks like they haven't made it any better.

 

[BeechIT]

The AEB has always been on on mine, until this evening, it’s now getting turned off with the LKA on every journey.

The AEB has went off twice with me in 3400 miles, and both time have been within a week of each other.

Last week, about quarter past midnight after back shift. M8 motorway, 40mph average speed cameras due to roadworks. No cars for at least a quarter mile ahead or behind me, cruise control set to 40 for the last mile, and all of a sudden, bang, brakes are slammed on hard out of nowhere, absolutely no reason and scared the hell out of me.

2nd time was this evening, sitting 2nd in queue at a red light, single carriage way. I was turning right, indicator on. Lights go green, first car goes straight on, I pull up slowly to the middle of the junction, slightly to the right, again, wallop! Brakes on hard to a stop. Was only doing maybe 4-5mph, didn’t stop me or the guy in the car behind me getting a scare. There was traffic coming the opposite direction on the carriage way, but nothing that should have kicked the AEB in.

To add insult to injury, I washed the car this evening and found more stone chips, this paint is crap! And I took the covers off the alloys to clean them and all my spokes have the “Z” scratch marks on them from the covers. Its booked in for the middle of the month to get the passenger door handle replace due to the button failing, so I’ll have a moan at the service guys while I’m in.

I’m just gonna live with it till it’s pcp is up, but I’ll not be buying another MG after this one. Sorry to say, I wish I kept the Megane or Mini order I had cancelled for this!

July 2024, ER Trophy 2022 Model - I just had the exact same issue as the driver reported further down the list. It happened to me today, I'm turning right, waiting for the lights, went green, pulled forward slowly, wham! Brakes slammed on with warning alarm, rear view cameras stuck on visible, for absolutely no reason at all. Good job there was no one behind me.

I've have had a few technical and other issues with this MG4 Trophy ER so far and I'm not impressed.
1. Bluetooth reconnecting on returning to the vehicle is useless. I've lost count the amount of times I've had a pair code pop up whilst driving and had to pull over to reconnect. I have never had this issue with the same phone on any other car. This has to be fixed ASAP.
2. 4g SIM not showing any signal, again lost count, have to reboot the whole Shitfotainment Systen to get a signal.
3. Electric windows non responsive after second press
4. Drivers seat seems to adjust it self, I set the seat up, which took me 2 months to set in a semi comfortable position, and it still isn't quite right, I've given up on it. The seat back rest is just too short for anyone over 5.7ft. And the head rest is too far forward unless you recline to gangster position, which i can't stand.
5. EVP access hatch not shutting properly, have to stop and give it a good shove
6. Washer jets poorly positioned, misty spray not direct jets, just useless.
7. Driver's seat is too far into the car, I feel like I'm really having to haul myself in and out of the car, dodging the outside door trim each time.

MG need to get their act together. Especially with the infotainment system, it would appear they have relied heavily on Android auto being connected to cover up all the poor programming and their apparent bugs.

 

[siteguru]

Typo ... Trophy ER and 2022 do not mix ... the ER wasn't available until later in 2023.

 

[hawleybeach]

I'm still in "Towing Mode". Zero beeping, no "Pre Flight Routine" required

Sometimes I have to press "Cancel" when it asks about "Towing Mode", but generally I just get in and drive

 

[Steve Kaye]

I had 2 similar issues with the emergency braking coming on while i had the automatic cruise control on. ( I have a 2022 ZS EV with 320km range)
Initially I discussed it with the dealer I purchased the vehicle from.
They gave me a load of BS, and basically said it was driver error.
I then contacted the New Zealand importer, told them it wasn't good enough.
They readily agreed to an in warranty check ( at the dealership where I purchased the vehicle from).
End result was: radar was mis aligned, plus they did two software updates ( not sure of the detail)
Learning point is, don't take no for an answer, if you think there is something wrong with your vehicle, there probably is.
If you come at it from a safety perspective, they should get involved in a remedy.
In New Zealand, we also have a Consumer Guarantee Act, amongst other things, the Act says that items must "be fit for purpose".

 

[NLMGSAN]

Did yours come to a complete stand still? Or more like ' a sudden brief braking' ?

 

[jollyman]

Did yours come to a complete stand still? Or more like ' a sudden brief braking' ?

My MG4 se did with a hell of a bang luckily no one else was involved as both incidents were at very slow speed just taking off at around 2-4 mph but it really scares you

 

[NLMGSAN]

My MG4 se did with a hell of a bang luckily no one else was involved as both incidents were at very slow speed just taking off at around 2-4 mph but it really scares you

Interesting... Before they fixed the lidar, if you were overtaking even a bit within the distance range set in ACC and you were in the other lane, did it initially still reduce speed?

 

[Steve Kaye]

Did yours come to a complete stand still? Or more like ' a sudden brief braking' ?

1 instance of a complete stop from 40kmph, scary stuff, and 1 instance of sudden brief braking

 

[NLMGSAN]

1 instance of a complete stop from 40kmph, scary stuff, and 1 instance of sudden brief braking

Did you also experience the car continuing to slow down with ACC on when overtaking a vehicle?

 

[Steve Kaye]

Did you also experience the car continuing to slow down with ACC on when overtaking a vehicle?

Yes at times but that can also mean its working as it should, eg if the car in front of the lane I've just overtaken into slows down in front of me, then clearly I'll slow down too

 

[NLMGSAN]

Yes at times but that can also mean its working as it should, eg if the car in front of the lane I've just overtaken into slows down in front of me, then clearly I'll slow down too

Maybe I should have been more specific: when in the other lane.

 

[securespark]

Not being contentious, just curious; do you think an insurance company would pull a face knowing that two safety features have been deactivated?

On the other side of the coin, would they happily pay out for an accident where a safety system activating contributed to the collision?

I know drivers following traffic should be able to stop in time, but does that still stand where cars are stopping on a sixpence randomly?

I mean, if a case like that went to court and there were witnesses to say there were no obvious reasons why the car jammed on, would the judge apportion blame to the braking vehicle?