Car brakes automatically when speed limit sign detected

[duckworthsj]

Has anyone had this problem ?

Situation: On a dual carriageway 110km/hr (70mph) limit with cruise control operating but AAC not.
Drive setting ‘B’
Passing a exit where there is a speed limit sign 80km/hr (50mph) for the exit, the car brakes automatically… from 115 to 80….
Which is like slamming the brakes on…

My wife says she is using the setting ‘B’ so understandable braking is more strong than in D, but never-the-less I can imagine a driver in a following car might have a panic attack… not to mention ‘tail-gaters’ ending in the rear seats.

Obviously the sign recognition system is detecting the 70km/hr on the slip road. My car (non VW) also often notifies me of ‘speed limit change’, so not unusual for cars to be confused…
I checked the speed recognition settings in the infotainment system and confirmed that the setting is ‘warn only’

Anyone seen this? How to correct it?

[MotMot]

I disabled this in the menu - and had no further problems. It’s a nice idea - but I’m happier reducing my speed rather than the car.

[sidehaas]

I've had this three times already in only a couple of days of motorway driving. Twice passing the same (M62) junction on the M57 in opposite directions, once somewhere on the M58. In all cases it tried to slow from 70 to 40 and in the third case I had just overtaken someone and pulled back in in front of them. However I knew what was happening from reading these forums in the past and immediately cancelled it by pressing the accelerator so I probably didn't lose more than 10-15 mph momentarily. The driver behind probably thought I was being a knob but they didn't have to brake much or at all.
It also fairly regularly gets the speed limit wrong due to missing a sign. It seems to always prioritise signs over map data. On another trip down the M58 it was warning me I was over a 50mph speed limit down the entire length of the motorway because it missed a sign for the end of some roadworks as I was coming off the M6. It also insisted to my wife that one of the roads in a local industrial estate was 5mph (it isn't.)
But on balance I find it very useful so I've kept it switched on. If you don't like it you can just switch it off.

[monkeyhanger]

I keep mine switched off. Most of these new driver aids are a safeguard against idiocy and can cause their own issues (lane assist pushing you towards a parked car you're giving a wide berth to etc.) allowing people to carry on texting or putting on makeup while they drive instead of keeping their eyes on the road.

[Daveion]

It can be a pain but I leave mine on. Its a way back for me but think its in the driver assist menus.
On regular routes and junctions I know when it will try to surprise and on new journeys its a useful backup to my own reading of road layouts/signage.

[G43FAN]

My wife says she is using the setting ‘B’ so understandable braking is more strong than in D,

B doesn't make the brakes stronger, it just applies them when you lift off. If the car senses it needs to reduce speed it will brake the same in B or D.

[Hemming91]

My wife says she is using the setting ‘B’ so understandable braking is more strong than in D,

B doesn't make the brakes stronger, it just applies them when you lift off. If the car senses it needs to reduce speed it will brake the same in B or D.

Sorry to hijack a thread! When using 'B' mode, as you say every time you lift off it auto applies the brake, do the brake lights show? I can imagine this being rather annoying for anyone in front if it looks like you are braking all the time!

[G43FAN]

Sorry to hijack a thread! When using 'B' mode, as you say every time you lift off it auto applies the brake, do the brake lights show? I can imagine this being rather annoying for anyone in front if it looks like you are braking all the time!

Yes they do in certain circumstances, discussed on a couple of threads already.. viewtopic.php?f=8&t=298&p=16007&hilit=b ... hts#p16007

Along with Brake lights and Auto Hold.

[Daveion]

I believe it does but is dependent on speed which led me to believe regen braking is more aggressive from higher speeds than at lower speeds.
Way back someone listed data on when regen braking activated brake lights but I cant find it now.

[Hemming91]

Sorry to hijack a thread! When using 'B' mode, as you say every time you lift off it auto applies the brake, do the brake lights show? I can imagine this being rather annoying for anyone in front if it looks like you are braking all the time!

Yes they do in certain circumstances, discussed on a couple of threads already.. viewtopic.php?f=8&t=298&p=16007&hilit=b ... hts#p16007

Along with Brake lights and Auto Hold.

Thanks!

[duckworthsj]

So if I understand the replies… if you want to stop the car braking on its own when the car detects a speed limit change, you have to turn off the ‘speed restriction recognition’ off ?

What an idiotic system!
Particularly when the speed limit sign is on the exit slip road, and your still travelling on the main carriageway.

I have never encountered that before. My own car and my wife’s old car both ‘WARN’ when they detect the sign ( can be visual and / or audio according to settings) but NEVER have I experienced a car decelerating on its own when it ‘sees’ a speed sign.
The speed notification/ panel recognition is useful… providing it allows me to take the decision.

[Deleted User 192]

The car obeys speed limits - even the ones it misreads.

It also uses GPS data to try and work out where you are, not just the front camera.

So yes, stop it reading/evaluating speed limits and it won't slow down for them.

My wife's Toyota Yaris doesn't slow down for speed limits, which I'm glad about seeing as it thinks the main road near me is only a 20 when it never has been and there's not a single sign along it which says 20.

[sidehaas]

So if I understand the replies… if you want to stop the car braking on its own when the car detects a speed limit change, you have to turn off the ‘speed restriction recognition’ off ?

What an idiotic system!
Particularly when the speed limit sign is on the exit slip road, and your still travelling on the main carriageway.

I have never encountered that before. My own car and my wife’s old car both ‘WARN’ when they detect the sign ( can be visual and / or audio according to settings) but NEVER have I experienced a car decelerating on its own when it ‘sees’ a speed sign.
The speed notification/ panel recognition is useful… providing it allows me to take the decision.

That's because your other cars are/were less advanced.
You can stop it using the speed limit cameras to affect the cruise control, and separately still ask it to display the limit with a warning symbol if you exceed it. Or vice versa. I'm sure it's all covered in the manual, otherwise just have a play around the menus while parked, that's what I did. You have the choice.

[steve]

I was thinking the other day that my id3 is making more mistakes about the speed limit the past month or so. More likely to see a side road's limit and tell me I am speeding. On the A9 around Birnam there are speed limits just for trucks which I'm sure the id3 never used to worry about but which now lead to rapid deceleration. I wonder whether 2.3 made it more able to identify speed limit signs that it previously missed?

[DumfriesDik]

My current car, Mazda CX5, spots the 40mph truck signs on the 60mph A road and warns me about speeding. Is the suggestion that the ID3 may brake every time?

[Deleted User 192]

My current car, Mazda CX5, spots the 40mph truck signs on the 60mph A road and warns me about speeding. Is the suggestion that the ID3 may brake every time?

You had a thread about this: viewtopic.php?f=8&t=1493

[duckworthsj]

Thanks for the suggestions.
I havent found a way to disable the speed limit sign recognition separately from the automatic braking action resulting.
I will re-read the manual specific to the chassis number and ‘play’. Then go to see the concessionaire if all else fails.
However I do remember that there was a discussion in the EU Commission / Parliament that they ‘would like that all new cars from date XXX automatically obey the speed limit’…. Maybe another EU control of our lives done by stealth….

[G43FAN]

Thanks for the suggestions.
I havent found a way to disable the speed limit sign recognition separately from the automatic braking action resulting.
I will re-read the manual specific to the chassis number and ‘play’. Then go to see the concessionaire if all else fails.
However I do remember that there was a discussion in the EU Commission / Parliament that they ‘would like that all new cars from date XXX automatically obey the speed limit’…. Maybe another EU control of our lives done by stealth….

Hardly by stealth, some vehicles have had a form of this since 2015 and the regulation/law was agreed in 2019 when we were still part of Europe.
The system can be switched off and currently a hard press of the accelerator will also override it, much to the ETSC's dismay.

Although if you read the Daily Express the EU was going to disable people's engines if they exeeded the speed limit.. we really need to get a grip in this small group of countries..

[DumfriesDik]

You had a thread about this: viewtopic.php?f=8&t=1493

So I did! What a plonker! And what a good memory you have, thank you.

[sidehaas]

Thanks for the suggestions.
I havent found a way to disable the speed limit sign recognition separately from the automatic braking action resulting.

Go into the 'driver assist' menu in infotainment.
It will look like a bluish image of a car.
Click on the coffee cup sign or the layby and check 'driver alert system' is active.
Next click on the car in front, this is the ACC menu. Disable 'speed limit preview' - this should stop the car slowing or speeding up automatically when you are in ACC.
Next click on the road sign and set 'speed warning' to either visual or visual/audible - this should provide the visual signs and warnings you want.
I haven't actually driven my car without the speed limit preview yet but I'm fairly sure that will do what you want. The eco assist will still slow the car sometimes for bends etc. If you want to disable that, then from the same driver assist menu click on the circle with three lines in it, top left. Eco assistance is second from bottom of the list you will see.