Traction Control Issues

[Benny]

I just thought I'd mention this problem I had a couple of weeks ago with my traction control.

I had to take my front two 18" alloys off to get buckles removed after my misses thought she'd aim for a few pot holes . So while the 18's were in for repair I fitted some standard 16" steel wheels from an XT. While driving on these wheels I noticed that every so often when accelerating the traction control light flashed and loss of power was experienced. The only thing that I could put this down to is the difference in rolling diameter from the front to the rear causing the traction control to think the the car was out of control. I have 235/40/18 rubber.

When I re-installed the 18's on the front the problem went away. Which cancelled the idea I had that maybe and ABS sensor was playing up.

So has anyone else got any theory as to what it may have been?

[100%]

I know what it is.

It's called sedanitis and it's an affliction that only effects cars with four doors and small boots. Easily fixed too, straight back to the dealer and trade her in on a UTE

Why can't we all live in UTEopia :spinaround:

[mickq]

No idea.

The TC sensors are tied in with the ABS. Unless the sensors thought the wheels were locking or spinning, then they would not have engaged the TC.

That weird. Perhaps the smaller than standard rims (16" vs 17") interfered with the ABS sensor causing it to produce inaccurate readings....leading to TC bring triggered off when it should not have been.

...or perhaps the car thought it was now an XT, and applied the same rules as would apply to an XT, so anything more than half throttle made the car think it was out of control and better slow down!

[Guest]

Benny,tell us more about your wheels buckeling,how bad were the pot holes? Bdennis (big lap) had this also 17" I think..

sound like garbage mags to me if this sorta stuff is hapening.

How do thet fix em? like an alloy head or what ?

vik

[GOLDIE]

The traction controll would have seen a different signal from the smaller wheels and would have acttaved due to different wheel speed front to back as this is what it does if you have wheel spin.

Ian

[Benny]

  iaschmidt said:

The traction controll would have seen a different signal from the smaller wheels and would have acttaved due to different wheel speed front to back as this is what it does if you have wheel spin.

Ian

That's exactly what I thought. I didn't think that the Traction control would be that sensitive between the standard XT tyre size and the size of the 18's, but guess it is.

As for getting the wheels fixed. I got the tyres stripped off and took the rims to Promac Engineering 02 49568466 in Newcastle. They straighten the wheels if needed and remove any dings. Then the wheels are placed in a large lathe to make sure there straight.

I was a bit worried about them getting scratched but they use special covers to prevent damage.

It doesn't take a very large pot hole to ding 18's even with 40 psi in each tyre.

[mickq]

  iaschmidt said:

The traction controll would have seen a different signal from the smaller wheels and would have acttaved due to different wheel speed front to back as this is what it does if you have wheel spin.

Ian

But arent the spare tyres (space savers in this case) the same size (ie 17" or 18") as the main tyres? I know they are skinnier etc, but I thought the diameter of the spare tyres rubber was the same.

Anyone know?

If they are indeed the same, then it doesnt explain the TC issue as the wheels would still be rotating at normal speed.

If they arent the same, then the idea of driving on 3 x 18" or 17" tyres and one 16" or whatever space saver tyre is frightening. Talk about unpredictable handling! As if the tyre being thinner wasnt enough!

Hate to drive an XR6T like that in the wet even doing it carefully. Scary stuff.

Luckily I have premium brakes so its not an issue for me.