I think I somehow accidentally put on the speed limiter (cruise control?) while driving my 2021 Fiesta yesterday (I’ve had the car for a year). I was just turning off a roundabout. The accelerator stopped responding properly and a small green light came up on the dash followed by a number. I had no idea what it was or what was happening. It’s not happened before and was quite scary in the  middle of traffic. I was luckily able to quickly turn down a side road and stop and switch off. When I restarted the engine, everything was back to normal. Can someone tell what I did to make this happen, so that I can make sure I don’t do it again. Please. 

Without seeing the switches you probably pressed the ASL (speed limiter) button on the steering wheel, which defaults to "intelligent", which means it sets to the current speed limit

That button is labelled "LIM" on my Puma (which is just a jumped up Fiesta) on the left hand side of the steering wheel. If you had hit the cancel button on the left hand side of the steering wheel, or the LIM button again, the speed limiter would have been cancelled. 

This sounds like poor design to me.  No switch on a car should be easy to accidentally operate.  As she says:

2 hours ago, Penelope said:

was quite scary in the  middle of traffic

Bordering on dangerous.

You really need to read the section in the handbook**on speed limiter and driver assistance. In vehicle settings you can choose between intelligent speed limiter and "basic" where you have to press the limit button then set the speed, so it sounds as if Intelligent has been ticked in settings at some point.

It shouldn't interfere unless it has detected you are over the limit (though the camera can occasionally miss or mis-read signs, as mentioned in other threads.) I use the ISA quite a bit and have experienced this on a local roundabout where the signs are badly placed.

I've been driving Mk 8/8.5 Fiestas for over 7 years and find "LIM" needs a deliberate action to switch on - it's the innermost button on the left hand spoke so quite hard to do accidently with hands in a normal position on the wheel, I would have thought. (Unlike the "haptic" touch pads on some VWs, I believe!)

**Download here if you don't have one: 

https://www.ford.co.uk/support/vehicle/fiesta-2017/2021/owner-manuals

1 hour ago, Paulkp said:

Bordering on dangerous.

I use the intelligent speed limiter every day. It only takes you by surprise if you haven't read the manual and understood how it works. It only limits your speed, if it does that unexpectedly you can hit the big cancel button which is next to your left thumb in a normal (modern 9 o'clock, 3 o'clock) driving position and all it will have done is slow the car for a fraction of a second.

Thanks for all the replies. I still don’t know quite how I managed to press that speed limit button by accident, turning left off the roundabout. But at least I now know where it is and can turn it off again by pressing CAN.  However after having had my previous Fiesta for 14 years, it’s made me realise how much more sophisticated the newer models are. My old one had none of these buttons. 
Eric and Paulkp, you’re both right. I DO need to properly read the much longer online version of the users manual.  There are 23 pages on cruise control and limiting speed. I started them today..😵‍💫

Thanks again, everyone

Edited September 8, 2025Sep 8 by Penelope
Just added a bit more

51 minutes ago, Penelope said:

There are 23 pages on cruise control and limiting speed. I started them today..😵‍💫

You can always pick up "War and Peace" if you need a break!😀

Good idea, Roger! I’ve got a copy of War & Peace somewhere. A bit of light relief.
I’ll go back to the car manual later…