Traction control light comes even when not hard cornering?
 

Hey guys,


This problem has come to me ever since two days. My car has a rocket bunny kit with wider wheels so I'm not sure if this happened because of the wider wheels but the car was just fine with the new wide wheels for over a week. Anywho, I started and warmed her up, I reversed out of the garage and as soon as I steered I heard a bit of a bang in the front, felt like the steering rack, the usual sound of metal not moving for a while and then moving it after a long amount of time, car is usually parked in shade and only driven in weekends. That bang made me a bit curious to know what it might be but I ignored it anyways. Then, as soon as I was in the highway the car would feel a bit wobbly as the steering wheel is not just feeling right. I ignored it and when I came to a corner to go up a bridge, the traction control starts to come up and lights up every single second and the usual ABS sound coming, the car braking and so on. At that time I was scared and did not know what to do so the first thing I did was to go to my alignment shop and have the car checked, everything was perfectly correct, they checked the tie rods, the alignment, the steering rack, everything was okay.

Today, I decided to fit my old wheel setup (pre rocket bunny) just for the sake of knowing whether this is because of the wide wheels or not and the same thing happened, it would happen at hard cornering and sometimes even not-so-hard cornering, in the past I have been hard cornering much much more than what I tried and the traction light never ever came up.

I'm not sure what the cause is, if it's something out of my hands then I have to take it to the dealership otherwise someone may have had the same experience and could chime in and help at least.

Thanks.

Did you try turning off the DTC/ASC by holding down the button? If that still caused it to happen, did you try the parking brake startup sequence to disable all assists?

If yes to both of these questions, I'd put the stock wheels on it and take it to the dealership. It could be a major mechanical problem with the rear diff (locked) or a strange electrical fault.

I tried turning off the DTC, still happened. Parking brake startup sequence I have not yet tried but please enlighten me with the steps.

are your tires front/rear much different in diameter? The ABS sound (if you're not locking them up yourself from hard braking, etc) is the stability computer trying to make a correction.

Search for the "pedal dance" to disable everything. I wouldn't recommend doing this for daily driving, but could be helpful to troubleshoot since it disables everything related to stability control.

Here's a video of the pedal dance. If your wheels are a different overall diameter (wheel + tire) the lights would probably come on in a straight line. Sounds like it only happens when turning, right?

[ame]http://youtu.be/CWXv7UNA7hg[/ame]

Be wary. The pedal dance turns off all assists except ABS and should only be used for hooning in a safe environment. It automatically resets back to normal the next time you start the car.

Fronts 18x9.5"

Rears 18x11"

If by diameter you mean are in different sizes (18 and 17 for example) then no, every wheel setup I have for this car are all the same sizes in diameter.

I don't think it has anything to do with the tire sizes not being the same in front as to the rear? Hell, I don't even think it matters if the rear tires are different than the front tires in terms of the tread style or brand.

ABS sound comes when cornering without me even braking.

Yeah I could use it to narrow down what this issue could be, whether mechanical or electrical.


Straight is just fine but the car would feel a bit wobbly even when overtaking cars, ever used a logitech g27 steering wheel? know that force feedback when you're turning and the steering wheel wants to go back to the middle? same thing happens when I try to overtake cars too just not too notice-able.

I'll try the pedal dance and see if the problem still persists.

check your front suspension,
my friend had the same problem and it turned out one of his front suspension components was slightly bent.

when he was turning faster then 20mph or actually even slower his traction light would go on and car would wobble like crazy.

I'm not referring to rim diameter, I'm referring to tire diameter, meaning the outermost edge of the tire. The most exact way to find this is to use a measuring tape to get circumference, and then math it to get diameter.

Consider a drag car using 18" front wheels with tiny little tires with a 22" total diameter, and tiny 15" rear wheels with gigantic tires at 32" diameter.

Point is, if there is enough difference, they will rotate at slightly different speeds, which could look like a problem to the CPU. When you turn, there's another speed difference between the inner and outer wheels. The CPU knows that you're making a turn from the various sensors, but if the wheel speed between the inner rear and outer front tire is even greater than expected parameters, again it might look like a problem to the CPU.

Mine would do the same thing but wouldn't wobble at all, the steering wheel would feel just fine when turning but the traction light comes on and that annoying ABS sound and braking happens. I will check on the front suspension though, the wobble I was mentioning is when overtaking in terms of the steering wheel trying to force itself to go back to the middle or when trying to corner had/semi-hard the rear feels wobbly as in I know the car used to be much more better at being stable when cornering and not feel a bit wobbly in the rear.

Why do people do the pedal dance when you can just hold the stability control button down for more than 3 seconds to get the same results? Maybe like to dance with your car?

Example at 1:41
[ame="https://www.youtube.com/watch?v=dj7WIlliwgQ"]Subaru BRZ drift secrets, stability control, VSC and TRC settings - YouTube[/ame]

Hmmm,

I'm running 255/35 for rears and 225/40 for the fronts, is this the issue?

I actually thought about that when going for the bigger tires at the back, now you've reminded me! I thought hmmm, there's a notice-able difference in tire sizes, won't this be an issue?

That's what I did in terms of turning off the DTC, held that button for 3 seconds and then 3 lights came up indicating that the traction is off.

Holding the button down for 3 seconds isnt the same as doing the pedal dance

Then problem narrowed down:

1- Suspension/suspension components have to be checked on all sides.
2- Tire sizes
3- re-check the steering rack for something suspicious.

EDIT: searched google and saw that there was a guy with a different car having the same issues when tracking, tires had different diameters, especially that the 225s I'm running in the front are a bit stretched compared to the rears which are not at all. I'll have the tires changed and then let you guys know. Thank you everyone for the help! really appreciate it.

Shouldn't be an issue, you have to remember hwen you stretch tires the car won't feel right and when you change lanes you will feel the car pulling you to one side or the other ( the lane you were on or the lane you are going to)
I had 215s on my 9.5's, and when anybody would drive my car he would go "WTF"

Another culprit could be toe, are you sure it's zeroed out?

Because the system isn't completely off, traction control is still slightly on and will engage when the car is at the limit.

Pedal dance is great to isolate problems or drive your car with ABS on but without all the nannies. It will only reset the next time you crank the car.

-alex

The '35' and the '40' in the numbers above are what tell you the sidewall aspect ratio
The '255' & '225' are the widths, and everyone knows the 18 is the inner diameter.

So your tires are different outer diameters, but not by much.
Your fronts are 18 inches (457 mm) + 2*(.40*225)= 637mm
Your rears are 18 inches (457mm) + 2*(.35*255)=635.5mm
I doubt that is your problem....

also make sure the tires are on the right way some tires are directional
its always good to check that.

yeah i would look around and see if anything is damage if it is still happening then bring it to the dealer or a shop that know what there doing.

You don't multiply by two according to TireRack.
225 x 0.40 = 90mm
255 x 0.35 = 89.25mm
So that's a difference of 0.75mm.

That's assuming they aren't stretched or otherwise out of standard spec. He says the rears are 11". The 255 is a 10" tire, so that's definitely stretched. Front is 9.5", but the front tires are 8.85", so those are stretched too. I'm leaning toward the tires not being a close enough diameter due to the stretch.

Another possibility is maybe the DTC/ABS cable is getting rubbed.

Ah... you are correct.
I thought the result was for one sidewall height, and it is for both.

I have felt that stretch grip reduction in my previous setup I was stretching all 4 tires but no matter what I did traction control wouldn't come on and when it did it was because it was a very very hard corner and it would just come up once and that's it.

Toe is 0 that's the first thing I checked, I remember a friend had some issues with stability and it turned out to be a toe issue so toe isn't an issue for me. Thanks SMS.

So pedal dance is slightly different than holding the button for 3 seconds?

Still, I'll check on the tires and have them swapped to bigger tires then if the issue still remains, then my best guess would be the steering rack.

Yep, gonna do that today hopefully.

Hmmm, that helps a lot! let's see if it turns out to be the front tires today and I'll let you guys know.


Any idea where that cable is located?


Again, thank you all for the help!

Holding the Trac OFF button for 3-5 sec will disable traction control 100%, and vehicle stability control about 98%, but leaves ABS active. If the car is under certain conditions (such as really aggressive track driving and trail braking over rumble strips) the CPU will still intervene a bit.

For you, holding the button for 5 sec to turn everything "off" should be sufficient. It's good enough to go drifting or hooning around in a street car.

The reason for you to do the pedal dance, is if the system continues to intervene when turned "off" by holding the button. In this case, the pedal dance will completely disable the system entirely (except ABS is left on). This will let you drive the car by itself to see if it's doing anything strange mechanically, or if the CPU is causing it.

If the CPU is indeed the problem, the next step is to determine if the CPU (or it's sensors) are actually bad, or if your mechanical setup is simply causing the CPU to intervene excessively.

Problem is 80% fixed!

After a long day of zero'ing out toe, checking the steering rack, checking suspension and components for anything and then looking for tires that would measure the same in height in the front as to the rears... the toe didn't solve the issue even though it's 0, steering rack completely fine, suspension and components fully fine. Tire sizes... here was the problem, couldn't find anything that would be fit in the front bigger than 225/40 as rubbing was an issue plus it was very very hard to find anything bigger in that size around the area I was in.. then 2 hours later me and a friend had an idea where deflating the tires to get the same difference in height would happen, we measured the differences before and the difference was 1MM believe it or not! all tires were on 40 PSI, deflated the rears to 32 PSI and the fronts to 30 PSI, BAM, 80% of the problem is gone, it would still do the traction thing at verrrry hard cornering and would feel a bit wobbly when steering at verrry hard corners but overall I'm much much happier than what I had two days ago. Till then, this is the temporary solution until my tire guy gets me the sizes that are appropriate, any tire sizes recommendations are welcome!

Different tire sizes (circumference) front & rear will cause this...

Guys, yes tire diameters different front and rear will cause this issue. however, OP indicated 225/40R18 front (25.1" dia) and 255/35R18 rear (25" dia). This should not be an issue, the computer is not going to pick up .1" difference. The answer lies in the heart of the stability system itself. When you align one of these modern vehicles, they have a steering wheel position sensor. If you change toe more than just a nudge, the sensor has to be re-learned to center. If not, you will get these issues. I run a shop specializing in alignments and this has been an issue for us. I'm not sure the procedure for the twins, but I am going to check my alignment machine and let you know.

Looks like you need a techstream or comparable diagnostic computer to perform "VSC sensor neutralization". That would be where I'm leaning.