Traction control

[MMG1989]

Hey wazup guys im trying to get a response to a lil problem im having when i drive with the TC on it will not accellerate i have to drive with it off and it drives perfectly fine but i just put some new saleen rims on here also. Any opinions?

[Bluerauder]

Hey wazup guys im trying to get a response to a lil problem im having when i drive with the TC on it will not accellerate i have to drive with it off and it drives perfectly fine but i just put some new saleen rims on here also. Any opinions?

Yep, your tire/wheel size combination is outside of the tolerances. Check your sizes front and rear. There must be no more than a 5-6% difference or less that about 2% to cause this. Are you running the same size all around?? That'll do it too. The MM looks for a differential in sizes front to rear. Your symptoms also show up almost exactly if some inexperienced shop rotates your tires creating a mismatch in sizes front to rear.

[SpartaPerformance]

I agree, the tire diameter of your new rims is not the same as the factory causing your issue.

[MMG1989]

Yea i have 18x9 in front & 18x10 at back with 245/45 & 275/40

[Bluerauder]

Yea i have 18x9 in front & 18x10 at back with 245/45 & 275/40

Yep, that combo gives you pretty close to same diameter tires all around. Tire height front is 26.68 inches, height rear is 26.66 inches (Revs per mile about 756 for both). Actually smaller than stock sizes for both.

OEM Stock size is 27.25 inches front (740 Revs/Mile) and 28.61 inches rear (705 Revs/Mile). OEM rear size is 5% taller than the fronts. The TC looks for that 5% difference (give or take some buffer [generally accepted here as between 3-6%]). With same size tires all around the TC thinks one set of wheels is slipping and it tries to counteract the problem by applying brakes and trimming power. That's why you get the issue when trying to accelerate. Only fix is to turn off the TC each time you start the car or switch to tire sizes that maintain that ~ 5% height difference.

Either way, we found your problem. The standard $89.95 diagnostic fee applies.

[Vortech347]

This is the only thing I DESPISE about our cars.

[Rockettman]

Yep, your tire/wheel size combination is outside of the tolerances. Check your sizes front and rear. There must be no more than a 5-6% difference or less that about 2% to cause this. Are you running the same size all around?? That'll do it too. The MM looks for a differential in sizes front to rear. Your symptoms also show up almost exactly if some inexperienced shop rotates your tires creating a mismatch in sizes front to rear.

This was exactly my case when I bought mine.
When I test drove it; the traction light would come on; and I got out and checked the tires.
They had swapped the backs to the front and vise-versa.
So I told the sales guy, "man I'm gonna have to get the computer looked at; maybe the axles; etc."
I knew what it was; he sure didn't! I brought the price down $5000 because of it!

[Mac-MerC]

This is the only thing I DESPISE about our cars.

only thing u despise about the 04'.. 03' doesn't have this issue

[Bluerauder]

only thing u despise about the 04'.. 03' doesn't have this issue

Not true at all. ^^^^. The 2003 300Bs all have Traction Control. Only the '03 300As won't have the problem 'cause they didn't get TC. I still remain baffled at how many folks still don't understand the 300A vs. 300B thing. The addition of traction control is what caused the major differences in the elimination of certain features to pay for the TC.

[Mac-MerC]

just for u Bluerauder

only thing u despise about the late 03' and 04's... the early 03's don't have this issue.
I understand the A and B model thing. i was just quick to respond. i have a A.. so i really don't care about the B's.. just being honest. but from what i always hear about the TC.. glad i dont have it

[Vortech347]

My 03' did not have traction control but the ABS computer is calibrated as well. If you put the wrong size on the ABS goes nuts after 80mph. Which is scary has hell going 140 and having the ABS kick on when you apply the brake. So it does matter even if its an A or B. They both have the same ABS computer.

[MyO4Rawdur]

Rims that arent factory sizes also mess with your speedo because it doesnt know the rotation numbers.

[Vortech347]

Rims that arent factory sizes also mess with your speedo because it doesnt know the rotation numbers.

Nah, its mainly the overall revs/mile like bluerauder mentioned.

[Bluerauder]

Rims that arent factory sizes also mess with your speedo because it doesnt know the rotation numbers.

His speedo should be registering about 7% higher than actual due to the smaller tire diameter on the rears. The speedo will read 64 MPH at a true speed of 60 MPH (756 revs/705 revs * 60 = 64.3 MPH) with that tire combo vs. OEM Stock sizes.

[MyO4Rawdur]

His speedo should be registering about 7% higher than actual due to the smaller tire diameter on the rears. The speedo will read 64 MPH at a true speed of 60 MPH (756 revs/705 revs * 60 = 64.3 MPH) with that tire combo vs. OEM Stock sizes.

yea thats what i was thinking but i didnt really know the way to figure it out haha im not even sure where i heard it but it just makes sense that the speedo would be off a little bit because of the change. those numbers sound like a automotive engineer talking.