Lude Generation

Last night we fitted a new set of wheels with 205/55/16 tyres instead of 205/50/16 tyres to the rear of a type s, at the same time we also fitted new front disk.

Since doin this the car has thrown up a warning light that looks like an axle but were not sure what's caused it, could the tyres cause this or have we messed up something on the front?

Any ideas?

Thanks pete

You have different profile tyres on the front (55) compared to the rear (50)? If so I think that will be your problem. Have you got the ATTS fault code?

I have no clue about ATTS, but wouldn't different tyre circumferances and therefore different rolling speeds front and back screw up the calibration?

yep. even a stone lodged in the tyre tread will throw a code.

very sensitive if out of whack.

We haven't pullled the code but yeah I think it's the tyres throwing out the atts but were gonna get some new ones tonight and hope it'll just clear itself??

Cheers

If a stone in the tread is enough to through a cell, wouldn't uneven wear between front and back tyres throw a cell too?

... Man ATTS is jobby!

thanks nathan your opinion is valued. What you have to say is important and valid. well done.

by changing the rotational speeds of the wheels you are confusing the wheel speed sensors so atts is unable to sum the wheels input. this will throw a code as your messing with the preset values atts works to.
Atts will throw a code when it feels an obvious and fast onset change in balance between wheels. As i said. if you pick up a decent size stone in your tread you will throw a code as the system treats this as a hazard to operation. which it is.

lewd lude lover wrote:thanks nathan your opinion is valued. What you have to say is important and valid. well done.

Thank you

In reference to my "sensible" related comment though... Does that mean uneven tyre wear would throw a code? Going by what you have just said, I assume it would. And therefore as with most thrown CELs does it then go into safe mode?

EDIT: Sorry, should I have put a "lol" or a "wink" after my previous comment? I see you - rep'd me.

... Nitin?

no. uneven tyre wear would be a slow unbalance and would not give atts a jump to account for. in this situation it would adapt.

but if your geo is properly out it would probably throw a code so you could get it sorted.

Got ya. I see that's what you meant by "when it feels an obvious and fast onset change in balance between wheels" now Thanks