MGS5 Auto Speed Limiter

[Thorin1962]

We drove to Peterborough on Sunday with the speed limiter switch on and set to Auto, as I was driving past the second slip road for Newmarket approaching the filling station on the A14 I noticed a horse box leaving the filling station and I indicated to pull out to the middle lane, as we got to the slip road, and half way through pulling out, the speed limiter decided I should be doing 15 MPH instead of the 70 MPH i was doing and started to brake the car. I was alarmed and had to remember how to switch the limiter off quickly before someone hit me from behind, on a busy road where pretty much everyone else is going at 70 MPH and our car braking was more than a little dangerous and certainly scary.

I switched the limiter back on afterwards and on the trip there and back it must have done this trick a good 6/7 times for varying speeds from 30 MPH to 50 MPH, one time there wasn't even a slip road !

Has anyone else had this type of issue before ?

 

[Alb]

AUTO isn't a good option for anything related to speed limit recognition.

 

[Thorin1962]

Agreed, but its Auto or nothing on these models. Other cars I've had I could manually set the speed limiter with no issues when left to me to manage

 

[Alb]

The speed limiter has a manual mode.

 

[Thorin1962]

Not that I've seen, nor the dealers who couldn't set it to manual.

Do you have any details as I would much prefer to set this manually ?

 

[TimothyN]

Long press the button and it goes to manual.

You can also switch off speed recognition altogether, as I have, because, as you've discovered, it's pants.

 

[Alb]

When every other option has failed, read the manual

 

[Thorin1962]

Long press the button and it goes to manual.

You can also switch off speed recognition altogether, as I have, because, as you've discovered, it's pants.

Thanks I'll give the long press a go and see if it is any good for me

 

[Robert Rush]

We drove to Peterborough on Sunday with the speed limiter switch on and set to Auto, as I was driving past the second slip road for Newmarket approaching the filling station on the A14 I noticed a horse box leaving the filling station and I indicated to pull out to the middle lane, as we got to the slip road, and half way through pulling out, the speed limiter decided I should be doing 15 MPH instead of the 70 MPH i was doing and started to brake the car. I was alarmed and had to remember how to switch the limiter off quickly before someone hit me from behind, on a busy road where pretty much everyone else is going at 70 MPH and our car braking was more than a little dangerous and certainly scary.

I switched the limiter back on afterwards and on the trip there and back it must have done this trick a good 6/7 times for varying speeds from 30 MPH to 50 MPH, one time there wasn't even a slip road !

Has anyone else had this type of issue before ?

I have used SL in manual for about 9 years and very recently bough an MG. I decided to try auto as I headed to a pub in St Neots, and had a similar thing happen with someone pulling out fairly far ahead in a 40 zone. I'll never use Auto again. The car following (too close) behind me ditched to avoid me. I'm pretty sure it's not the SL doing it, but the Assist, which I turned off the day I bought it.

 

[mg4 ade]

We drove to Peterborough on Sunday with the speed limiter switch on and set to Auto, as I was driving past the second slip road for Newmarket approaching the filling station on the A14 I noticed a horse box leaving the filling station and I indicated to pull out to the middle lane, as we got to the slip road, and half way through pulling out, the speed limiter decided I should be doing 15 MPH instead of the 70 MPH i was doing and started to brake the car. I was alarmed and had to remember how to switch the limiter off quickly before someone hit me from behind, on a busy road where pretty much everyone else is going at 70 MPH and our car braking was more than a little dangerous and certainly scary.

I switched the limiter back on afterwards and on the trip there and back it must have done this trick a good 6/7 times for varying speeds from 30 MPH to 50 MPH, one time there wasn't even a slip road !

Has anyone else had this type of issue before ?

I have experienced similar unplanned braking issues because the car reads speed signs for roads connected to the one I am on and not the one I am on, avoid auto control. My Tom Tom sat nav knows speed limits without having to read signs so it is possible do do this without cameras.

 

[TimothyN]

I say again, switch off the speed recognition, it is considerably worse than useless.

 

[RCK49]

We drove to Peterborough on Sunday with the speed limiter switch on and set to Auto, as I was driving past the second slip road for Newmarket approaching the filling station on the A14 I noticed a horse box leaving the filling station and I indicated to pull out to the middle lane, as we got to the slip road, and half way through pulling out, the speed limiter decided I should be doing 15 MPH instead of the 70 MPH i was doing and started to brake the car. I was alarmed and had to remember how to switch the limiter off quickly before someone hit me from behind, on a busy road where pretty much everyone else is going at 70 MPH and our car braking was more than a little dangerous and certainly scary.

I switched the limiter back on afterwards and on the trip there and back it must have done this trick a good 6/7 times for varying speeds from 30 MPH to 50 MPH, one time there wasn't even a slip road !

Has anyone else had this type of issue before ?

Yes. I use speed limiter all the time but have to keep an eye on it as at times it seems to have a mind of its own. There are certain places on my regular trip where it always switches from 30 to 40 and I can't see any reason for it. I have also had it drop down to nothing! and the car braking. The limit as you know is read by the front camera so it must (?) be picking up a visual input from somewhere. My old car (a RAV4) used GPS and that seemed to be a more accurate reliable system.

As an aside I would not use the limiter on an unrestricted road, cruise control would be a better option.

The whole system could do with a faster processor.