Traction control light w202

[horgantrevor]

Hi I have a long drive and a private road

I took the w202 c240 out running on 17 inch staggered Amg alloys monoblocks

Question

At 80 mph the traction control light keeps coming on then loose power unless you lift off
Also if I hit the traction control button too turn off the car keep s accelerating

Any ideas why it keeps coming on

 

[Stratman]

If your wheels are different sizes front and rear, it's possible the traction control is being fooled into thinking you're skidding, as the wheels will be turning at different speeds. As you go faster the difference is more pronounced and may be enough to trigger the TC, which will react by reducing the engine power and maybe braking a wheel or two.

 

[horgantrevor]

Yes I have staggered

17 inch factory mono blocks

245 40 17 back
225 40 17 front

When I had my 18 mono block s on I had no problem

 

[andy27168]

Hi Trevor,
The TC can be triggered as Stratman says, and looking at your tyre sizes it appears you have the wrong size front tyres fitted, they should be 45 profile, I think this would be enough to cause your problem.

 

[horgantrevor]

I'll check the tyre sizes again today

 

[horgantrevor]

Hi just ran out and checked I have the correct 225 45 17 on front

So back to square one still confused why this is happening

 

[vijilants]

Whats the profile on the rear....40 or 45 ?

I dont have staggered and have 225/45/17 on front and rear and don't suffer from the problems you are experiencing.

 

[horgantrevor]

They are the spec of the Amg w202 mono block
Front 225 45 17
Rear 245 40 17

I have never had this happen before

I usually run 18 inch monoblocks

 

[vijilants]

Those profiles would mean that the front wheels are rotating at a different speed to the rears.

I though the profiles on the C43 are the same front and rear...I could be wrong.

 

[andy27168]

Hi,
Profiles on a C43 are 45 front and 40 rear with 17" rims, 40 front and 35 rear in the case of 18" rims.

 

[Stratman]

Using this tyre size calculator (I put the front size in 'stock' and the rear size in 'new'), it shows they will be a 1% difference in rotation speed. This seems to be quite a small difference, would it be enough to trigger the ESP?

 

[horgantrevor]

I don't know

I must get it put on my friends star when he's back from holidays

Its strange I must say

 

[horgantrevor]

Solved the problem I have two sets of 17 inch amg mono blocks

I had put on one wheel with the rotation on wrong

It was part of another set I only saw it today

Sorry for the silly question

 

[kth286]

Solved the problem I have two sets of 17 inch amg mono blocks

I had put on one wheel with the rotation on wrong

It was part of another set I only saw it today

Sorry for the silly question

I don't get that - why would that trigger the traction light ? Anybody !

 

[horgantrevor]

Tyres are rotational meaning they must be fitted to correct side of car with the rotation of the tyre going in the direction of travel if not you loose grip

One of my rear wheels was not on right and was loosing grip bringing on the traction control light