Cruise control keeps turning off

[mattysupra]

Hi all,

I have a issue where if i set my cruise control above 65mph it turns off after 20 seconds or so. If i set it at any speed below 65mph it works fine.

Not sure if its related but my gearbox has started getting stuck in winter mode also.

Im guessing there is some sort of speed sensor issue.

Any ideas?

Thanks.

 

[television]

First do make sure that all the tyres are near enough all the correct size

 

[mattysupra]

First do make sure that all the tyres are near enough all the correct size

It has just had 4 brand new tyres and yes they are all the same size.

 

[television]

if a 210 I would clean up the wheel sensors particularly the reluctance rings on the rear axle.

The speed signal is taken from the front ones, this could affect the box at the same time

 

[Alex M Grieve]

Hi all,

I have a issue where if i set my cruise control above 65mph it turns off after 20 seconds or so. If i set it at any speed below 65mph it works fine.

Not sure if its related but my gearbox has started getting stuck in winter mode also.

I'm guessing there is some sort of speed sensor issue.

Any ideas?

Thanks.

The cruise control also includes a speed limiter, which you can set to the speed you do not wish to exceed. It can be over-ridden by the throttle.

I wonder if your speed limiter might have been set to 65 mph at some time? Perhaps that might prevent the cruise control accepting an instruction to go faster than that?

I don't use my speed limiter, and this is just a guess, but worth looking at the handbook and disabling that function.

I have found that when my cars don't behave exactly as I expect, it is usually a driver problem, not the car. :Oops::Oops::Oops:

 

[Naraic]

If a 210 the speed limiter and the CC can't work concurrently.

 

[Alex Crow]

could be corrosion on the front reluctor rings, cast as part of the front hubs. have seen this on the w210 a few times, starts dropping out at 65mph then the threshold drops.

 

[television]

could be corrosion on the front reluctor rings, cast as part of the front hubs. have seen this on the w210 a few times, starts dropping out at 65mph then the threshold drops.

Good thats what I said

 

[mattysupra]

Sorry for the delay getting back on here!


Well thankyou all for your advice. Im going to have a look at replacing these reluctor rings.


The abs seems to activate for a mini second every time you go to break so i guess this must be related.

I will let you know if i fix the issue.

 

[Naraic]

Sorry for the delay getting back on here!


Well thankyou all for your advice. Im going to have a look at replacing these reluctor rings.


The abs seems to activate for a mini second every time you go to break so i guess this must be related.

I will let you know if i fix the issue.

Explain that. There is something really wrong if it engages when you brake.

 

[npuk]

It has just had 4 brand new tyres and yes they are all the same size.

That doesnt mean they are correct and if it only started happening after the tyre change it would point to the tyres being the cause.

Check the size is correct as per owners manual and if a staggered setup you would have different size front and rear tyres.

 

[jonclancy]

Sorry for the delay getting back on here!


Well thankyou all for your advice. Im going to have a look at replacing these reluctor rings.


The abs seems to activate for a mini second every time you go to break so i guess this must be related.

I will let you know if i fix the issue.

I have both these problems as well. Any updates gratefully received, thanks Matty!

Cheers

Jon

 

[stevenN]

Wonder if the OP got it fixed?
My CC is doing the same.
Where will I see the bits that need cleaning?
The wheels will have to come off when I have another bash at the bumper.
Probably not till after the monsoon were expecting though

Cheers

Steve

 

[jonclancy]

Not sure, but today I tried the CC at 50MPH and it stayed engaged. IIRC, there is a speed (68??) where it tends to trip out.

Clean the reluctor rings or new hubs was on my list...

 

[bigasotonuk]

Hi,
If you tyres are the correct size, and you want to look at the front reluctor rings, you can see them once the speed sensor is removed though to clean them, you will need to remove the wheel hub, remove the caliper, and disc, remove the centre nut of the hub to remove the hub assembly, just give the reluctor ring a good wire brushing over possibly finishing with some emery cloth. I have this issue with mine at the moment, if the ring is to badly damaged/corroded it might require replacing which means you will have to replace the complete hub assembly. Be careful to keep the hub and the wheel bearing clean and free of dirt and grit, and when reassembling use a good quality HM grease.
On my car I got a diagnostic done which told me exactly which speed sensor was,nt working correctly.

 

[Alex Crow]

Good advice above.

The corroded front reluctor ring on the W210 series carts is very common, is not helped by cleaning them, and usually shows up with the cruise control cutting out at higher speeds. As the corrosion increases, the drop out speed lowers. Eventually this will start triggering ESP/ABS/BAS codes, as the signal gets worse.

Diagnosis is easy with Star and a co-piolt - just monitor wheel speeds at a steady 70 mph.
If you do have the classic problem, front wheel speeds will go up and down around 2mph with vehicle at steady speed. Rears will be much more stable.

 

[stevenN]

Hi Alex

Thank you for the info.
Is it as bad as a new hub or can I just replace the ring?

Cheers

Steve

 

[Alex Crow]

Steve,

The ring is cast, as part of the rotating hub assembly, so all or nothing really.
One of my customers suggested machining down the ring, and the mating surface for the sensor (to maintain air gap) - may well work...

 

[stevenN]

Thanks Alex

I will have a look to see if cleaning will help.
Otherwise a new hub is about £100 from ECP.
It had new discs a few month ago so everything should come off easy.

It could be related/connected to a vibration issue I have.
Just looking for a local alignment place to do a tracking and balance check.

Ta

Steve

 

[Naraic]

Thanks Alex

I will have a look to see if cleaning will help.
Otherwise a new hub is about £100 from ECP.
It had new discs a few month ago so everything should come off easy.

It could be related/connected to a vibration issue I have.
Just looking for a local alignment place to do a tracking and balance check.

Ta

Steve

I assume your tyres front and rear are worn to the same level. One extra worn tyre will kick out the CC.