Sudden automatic braking issue

[fshuk1]

Hi guys,
Just registered with this forum. Our company has an MG ZS 2022 model which is used by various employees for supply runs. Yesterday, our mechanic was on a trip when the EV's brakes locked up taking the car from 60 to 0kph in a second (emergency braking?) He reported no apparent reason for the auto-braking and sustained soft-tissue injuries to his legs from the incident (he is a tall-bloke).
Contacting the MG service dept with our concerns drew no interest from them. Vehicle had been serviced 2-weeks prior.
Is there a known sudden braking issues with the ZS model as per the above? Car has been tagged out-of-service until resolved.

First time I have read IN OUR FORUM that a car was travelling fast when this happened. It normally happens at low speeds so it is frightening but not life threatening. This now worries me. Have we had other instances of this with MG cars?

 

[Coulomb]

First time I have read IN OUR FORUM that a car was travelling fast when this happened.

The report is from Australia, so it was 60 km/h (about 37 mph), not 60 mph. 60 mph to zero in a second is almost impossible.

 

[Tuareg]

I would think 60kmh to 0kmh in 1 second would also be impossible.

 

[WonkoTheSaneUK]

I would think 60kmh to 0kmh in 1 second would also be impossible.

Not if there's a brick wall or tree involved.

 

[dan1845]

Yep about 30 mph the other day. Didn’t bring to total stop but enough to throw everything off seats etc. I was going over a slightly narrow bridge with queued traffic the opposite side

First time in a while mind

 

[fshuk1]

Yep about 30 mph the other day. Didn’t bring to total stop but enough to throw everything off seats etc. I was going over a slightly narrow bridge with queued traffic the opposite side

First time in a while mind

If you think about it the car sees you travelling at 30mph towards oncoming traffic.

Not sure what we can do at this situation. I would suggest put your indicator on. Anything to let the car software know you-know what is happening.

 

[Thebiglad]

This is unfortunately quite common on modern cars (not just MGs). You can turn the system off but I think you have to do it every journey. The technology is just not 100% there yet in terms of detecting a real threat. However, mine, buggy though it is, has saved my bacon a couple of times so I leave it on.

Initially I tried driving with lane keep assist on, and got a number of 'Phantom Braking' episodes which were unnerving to say the least. I put it down to the camera 'seeing' hedges/fences on sharp bends. As soon as I found a way of completely deleting this system I have no further problems.

 

[fshuk1]

Initially I tried driving with lane keep assist on, and got a number of 'Phantom Braking' episodes which were unnerving to say the least. I put it down to the camera 'seeing' hedges/fences on sharp bends. As soon as I found a way of completely deleting this system I have no further problems.

Please don't confuse Lane Keep Assist with Forward Collision system. LKA is shit and needs switching off. Sudden "Automatic Breaking" should not be initiated from LKA. You can set the FCS to Alert if you are afraid. My own feeling is I like FCS and it is better to learn how to live with it (ie indicating or not rolling towards a parked car etc). You may REALLY need it one day.

 

[OriginalBigAl]

In an effort to try to get used to this system here is an idea. Take some weak cardboard boxes and a quiet car park and drive up to them , normally, in neutral and rolling, weaving etc . See what the effects are (apart from looking like Bodie and Doyle) and it will give you some idea of the braking forces involved, along with the different situations. Understanding and not then being as surprised by the FCS can only help.

 

[Martinonline]

I have set FCA sensitivity to Medium and not had a problem with braking. I do get a warning when driving down a road with cars alternately parked each side (eg a chicane?) if the car thinks I'm going too fast. Otherwise emergency braking only occurs when I use ACC in limited speed zone with parked cars.

 

[NLMGSAN]

I do get a warning when driving done a road with cars alternately parked each side (eg a chicane?) if the car thinks I'm going to fast.

You mean the gong sound?
Mine comes up on each trip after about 10 miles, even if there is nobody around. Like saying "he, don't forget me.. "

 

[Rolfe]

I have set FCA sensitivity to Medium and not had a problem with braking. I do get a warning when driving done a road with cars alternately parked each side (eg a chicane?) if the car thinks I'm going too fast. Otherwise emergency braking only occurs when I use ACC in limited speed zone with parked cars.

What you describe is phantom braking, not emergency braking. Emergency braking is an extremely sudden stop.

 

[Tig170]

What you describe is phantom braking, not emergency braking. Emergency braking is an extremely sudden stop.

Must admit - that I've had this once or twice (or more) in the MG4 (early 2022 model (Sept)- now 18 months old) -usually in town, but also on motorways at 70mph+, so far not being rear ended but have been close mainly via lorries (as mainly cruise control at 60mph to ensure that I have enough charge) - I do have a fair few road rages from ICE drivers? - not sure why but i beleive my brakes (via regen kick in at around -13% )

 

[NLMGSAN]

What you describe is phantom braking, not emergency braking. Emergency braking is an extremely sudden stop.

This resembles what I experience on cross roads where cars brake to turn right while I simply want to go straight ahead. The MG than also brakes. Seen some middle fingers already....
The system relies on camera and liedar I read. My guess is it is biased too much to the sides. If others do not experience this at all, it probably is poor calibration causing it.

 

[siteguru]

Must admit - that I've had this once or twice (or more) in the MG4 (early 2022 model (Sept)- now 18 months old) -usually in town, but also on motorways at 70mph+, so far not being rear ended but have been close mainly via lorries (as mainly cruise control at 60mph to ensure that I have enough charge) - I do have a fair few road rages from ICE drivers? - not sure why but i beleive my brakes (via regen kick in at around -13% )

It's when the retardation rate exceeds a certain m/s² that the brake lights must come on (by law), thus whatever regen achieves this will put them on - I think this is closer to -7% regen.

 

[Seaton91]

First instance today- luckily the LR Disco driver behind me was switched on enough to slam on themselves.

Frightened my 6 year old son no end. Only doing about 20, following another MG4 at a steady speed, slowing to come to a roundabout. Oncoming traffic in other lane the only explanation I can think of.

Brakes definitely work!

 

[NLMGSAN]

Caused by another ... MG

 

[Deleted member 14300]

Please don't confuse Lane Keep Assist with Forward Collision system. LKA is shit and needs switching off. Sudden "Automatic Breaking" should not be initiated from LKA. You can set the FCS to Alert if you are afraid. My own feeling is I like FCS and it is better to learn how to live with it (ie indicating or not rolling towards a parked car etc). You may REALLY need it one day.

It's all camera related. I'm famous for the sticker over the camera. Switches so much off, but no phantom stops or LKA incidents. I originally thought sonar may cause it, but sonar sees cars up front but does nothing else.

 

[NLMGSAN]

It's all camera related. I'm famous for the sticker over the camera. Switches so much off, but no phantom stops or LKA incidents. I originally thought sonar may cause it, but sonar sees cars up front but does nothing else.

Depends on what you call phantom breaking. Breaking while overtaking is FCS relatedd. Phantom braking is something else.

 

[jollyman]

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.

I have had the same thing at very low speed ,fortunately ,but the car braked so violently it freaked me and my wife out.I was stopped at a temporary stop light ,pulled out when the lights changed and for a second the front camera must of picked up the hedge on the opposite side of the road and bang the emergency brake banged on,I swore so my wife clipped me round the ear