[gokeane]

I have a 2004 G35 coupe that has 27000 miles, I have recently purchased new rear tires, identical to the original and now in moderate cornering the traction control activates I am certain that I am not even close to pushing her hard enough to be loosing traction. This started immediately after the new tires were installed.Any ideas?

 

[thatguy]

So you're running new rears and old fronts, correct? All OEM sized?

Basically your new rear tires are larger in diameter now (no wear) and your fronts are smaller than originally designed (worn some). This difference in diameters is probably confusing the system.

Easy solution...turn it off

 

[Gilley]

^ that's a possibility.

Another is that the rear tires are slick at first and need to wear down the wax on them.

Another is that the older front tires do not have the traction that the rear tires have and are being over driven.

 

[JustJ]

Fresh rear tires not scratched in yet. New tires are always slick as snot until the release agent worn off, then they'll grab as designed.

 

[robbo]

Same problem with Traction Control

I'm dealing with the exact same problem. 2004 G35 Coupe, 26k miles. Original Michelin Pilot Sports. Fronts were at 7/32, rears at 3/32. I wanted an all-season tire that might last longer the second time around, so I replaced the rears with Eagle GTs from tirerack.com, installed at a local tire shop. I immediately noticed squirrely handling, with the SLIP light coming on during merely moderately aggressive turns - highway off-ramps at 60mph, for example. The SLIP light was accompanied by the feeling I was driving over rumble-strips - guess the traction control system tries to brake the car in some manner?

I rode on them for 1000 miles just see if they would break in. No luck. I went back to the installer, but they couldn't find anything wrong. Then I took it to the dealer. Their tech reported that the new rear tires had a different circumference than the original rear tires. He said the originals (new) were 81" in the front, and 83 1/4" in the rear. Now, my originals in the front were down to 80 3/4", and the new rear tires were 84 1/4". This means the difference between the two tires went from 2 1/4" inches to 3 1/2", and this was causing the problem.

For a second opinion, I spoke to a technical sales rep at tirerack.com. He said he could see that there might be a problem running with summer tires on the front, and all-seasons on the back. Different treads. We also noted that the original Pilot Sports had been discontinued by Michelin, replaced by the Pilot Sport PS2. This would also have a different tread, and he couldn't guarantee that these wouldn't have the same problem.

I opted to re-replace the rears with Michelins from the dealer. (Anyone want two lightly used Eagle GTs 245/45/ZR18? - motivated seller!)

Unfortunately...I'm still having the same problem. It's not quite as bad as before. But the bottom line is...my G35 Couple is handling like a minivan.

My next step was to search for a G35 forum to look for advice - and I found this thread within 10 seconds, describing my exact problem to a T.

My only option seems to be to ride it out. I guess I could drop another $600 on new tires for the front. I'd rather not.

The new info I've seen here is - I was not aware that the traction control system could be turned off. I don't have my manual handy - I assume this is something a mechanic would have to do?

But this to me seems like hiding a symptom when there is really a problem. The car feels squirrely even before the traction control comes on.

Any other thoughts or suggestions? Thanks in advance for your attention!

 

[Gilley]

The VDC can be mostly disabled by pressing the VDC button near the trunk release. The only way I know of to completely disable the system is to pull the brake fuse.

I replaced my PS2s in the rear with new ones and kept the worn PS2s up front and I did not experience this problem.

 

[jardolei]

It all has to do with tire circumference (like the dealer told you).
If there is a certain difference in circumference, the traction control thinks your "slipping".
I have the same problem as you are when exiting the highway too fast.
I have finished original tires in front (when I mean finished, its like 2/32 left)
The rears are new, so the rotational speed is different front vs back.

SLIP light comes on = ITS NORMAL and thats how it works.

What to do to fix it:

- Buy same tire all around (or keep circumference the same)
- press the VDC button (duh)
- don't take exits at 60 MPH (boo!)

Easy as pie

 

[emmett18]

i had a similar problem and it was that my front tires were old and rear were new, i had to replace the front also because they were not gripping as the rear were.

 

[Gilley]

- Buy same tire all around (or keep circumference the same)

Get the proper size tire all around. The front tires are shorter than the rear.

 

[JustJ]

I run same dia F/R with no issues. Think if 3%+ diff in F/R you're VDC will say nope, me no likey.

 

[ptbug123]

So you're running new rears and old fronts, correct? All OEM sized?

Basically your new rear tires are larger in diameter now (no wear) and your fronts are smaller than originally designed (worn some). This difference in diameters is probably confusing the system.

Easy solution...turn it off

thank you for this. We took our car to the dealer who could not seem to figure it out. Having read this it now makes total sense. We did the same thing replacing the rear tires but not the fronts.