ML270CDI Yellow warning ligh reducing power

[delboy642]

Hi please can you help me. While driving my 2002 ML the yellow triangle warning light started flashing and the power was reduced. After 5min it stopped. This has happend about 6 times in all types of weather conditions and speeds ranging from 50-75mph. Plus now I can only set the cruise control to a max 70mph, if I try to set it when running at 75mph it will not hold at that speed? I have had two new tyres fitted at the front and was thinking it might be thoes???? I have search other forums but cannot find anyone with the same problem.

 

[rf065]

Are the tyres the correct size for your car?

Russ

 

[delboy642]

Hi Russ, they are the same size that came off 255-65-17 different make though.

 

[rf065]

I'm sure someone with the same car will be able to confirm or deny, but I think 255/60x17 is the correct size?

Tire sizes Mercedes-Benz ML 270 CDI (2002 model for Europe )

Russ

 

[mersum1es]

Rotation circle of your tyres are now different (new vs. worn, and different make). Only other thing that may cause same problem is that one of your wheel rotation sensor has slightly corroded/giving misreading, and thus causing difference in speed signal.

 

[delboy642]

Thanks for your replys. Im going back to the tyre company tomorrow to see what they have to say and get to more tyres fitted. If that dont work im getting to it might be the break switch?

 

[WG M-B]

Not the switch no. This is a wheel speed issue. If its not the tyres then a faulty sensor or failed reluctor ring

 

[delboy642]

Hi been back to the tyre garage and they cannot find any fault with the tyres. On the way their i was putting my foot down a bit and the way back and did not get any warning light flashing on? So Im thinking its the wheel sensors. Has anyone fitted these and if so where are they and are they easy to fit? Plus it still Will not save any cruise control over 70mph

 

[mersum1es]

Tyres may be ok, but it does not help if radius of the front/back tyres are different! Did they measured it? (you can try measure distance from center of the wheel to the ground).

If there is problems with sensor itself, here are location of sensor (sensing ring is not shown)

http://www.auto-parts.spb.ru/cat/ca...1c0c93937300e201547486f2678455364594e34374a7c

 

[brucemillar]

I had this on my on my C55. What I noticed was that it would always happen when accelerating as I went over a slight hill/brow. It was the rear wheel sensor on N/S. Easy to change it just pushed out the hub with a slight tap from a nail punch/ The new one pushed back in with some anti-tamper fluid.

I think that STAR will show up a failing sensor. I seem to remember that was how I knew which one it was on mine.

 

[delboy642]

Hi, thanks for reply. Think its best for me to take it to a garage and get it on the Star system or I will end up changing all four sensors. Any recomendations were its best to take it to in the Newport SWales area?

 

[Stratman]

I'd have a sneaky 50p on a wheel speed speed sensor being disturbed when the tyres were changed.