New front wheels tires - "Traction System Active" Warning
Thread Starter
Racer
Joined: Nov 2006
Posts: 448
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From: Dallas, TX
New front wheels tires - "Traction System Active" Warning
All, I am running slightly worn 315/30/18's on the rear and just swapped from 295/30/18's to new 275/35/18's on the front and also went with a thinner wheel up front. I had the tire shop swap TPMS from old to new wheels as well. When I got home, I had to reteach the TPMS system at each wheel as it got confused on which corner was which. I've confirmed each wheel is now accurately reading, but here's the issue:
When I go over 50mph (around 52 actually), I get "Traction System Active". Is this because of the front tire diameter being larger than the rear now? Is there anything that can be done about it? Can I use my HPTuners software to adjust it out?
I'm doing an HPDE event tomorrow and don't run with AH/TC on but am worried the system will still intervene due to confusion or something (like when running without TPMS installed).
I would have thought a search would come up with a lot of hits for this message but was surprised not to find one.
Thanks!!!!
Dan
When I go over 50mph (around 52 actually), I get "Traction System Active". Is this because of the front tire diameter being larger than the rear now? Is there anything that can be done about it? Can I use my HPTuners software to adjust it out?
I'm doing an HPDE event tomorrow and don't run with AH/TC on but am worried the system will still intervene due to confusion or something (like when running without TPMS installed).
I would have thought a search would come up with a lot of hits for this message but was surprised not to find one.
Thanks!!!!
Dan
Safety Car
Joined: Feb 2002
Posts: 3,725
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From: Montoursville Pa
here is how to fix it for now, you can disable active handling by unpluging the steering position sensor on the steering column under the dash.
however you may not be allowed to run like that unless you are in an advanced group
however you may not be allowed to run like that unless you are in an advanced group
Race Director
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From: Hudson WI
NCM Sinkhole Donor
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Racer
Joined: Nov 2006
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From: Dallas, TX
Thanks for the info!!!
Thread Starter
Racer
Joined: Nov 2006
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From: Dallas, TX
I'm running R888's - the fronts are 1.75mm taller based on my math plus the wear on the rears so probably more like 2mm.
Thread Starter
Racer
Joined: Nov 2006
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From: Dallas, TX
Anyone know if turning off TC/AH will keep everything happy on the track despite this discrepancy in tire height? It might be my overactive brain, but I felt like the car was slowing down too fast when I let off the throttle at highway speeds testing it this morning so I was worrying about the brakes pulsing for Traction Control despite having it all turned off.
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Race Director
Joined: Oct 2002
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From: Southern CA
Anyone know if turning off TC/AH will keep everything happy on the track despite this discrepancy in tire height? It might be my overactive brain, but I felt like the car was slowing down too fast when I let off the throttle at highway speeds testing it this morning so I was worrying about the brakes pulsing for Traction Control despite having it all turned off.
TC/AH doesn't secretly turn itself on every so often just to check & see if you have taller fronts.
Thread Starter
Racer
Joined: Nov 2006
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From: Dallas, TX
So far as I know off is off, tc/ah should not be sensing tire height (rotations) at all. That's how my c5z is, run any tire size combo you want & no intervention if it's off.
TC/AH doesn't secretly turn itself on every so often just to check & see if you have taller fronts.
TC/AH doesn't secretly turn itself on every so often just to check & see if you have taller fronts.
I've had everything freak out on track when I was having TPMS struggles so I think I'm just paranoid!
Safety Car
Joined: Feb 2002
Posts: 3,725
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From: Montoursville Pa
So far as I know off is off, tc/ah should not be sensing tire height (rotations) at all. That's how my c5z is, run any tire size combo you want & no intervention if it's off.
TC/AH doesn't secretly turn itself on every so often just to check & see if you have taller fronts.
TC/AH doesn't secretly turn itself on every so often just to check & see if you have taller fronts.
depends on the code as to just what happens
Tech Contributor
Joined: Oct 1999
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From: Charlotte, NC (formerly Endicott, NY)
As long as you have your tire pressure sensors programmed correctly and they behave while on track all you have to do is turn off TC and you will be fine. If you want to run AH it will work since AH doesn't use wheel speeds to determine when to activate. AH activates based on steering angle, lateral Gs and yaw rate.
I ran a R888 setup that had slightly larger diameter tires in front than the rear and when I backed out of the garage at the track and started moving forward TC would shut me down before the car moved 10 ft. I just pushed the button until everything was off and never gave it another thought.
Enjoy your track time.
Bill
I ran a R888 setup that had slightly larger diameter tires in front than the rear and when I backed out of the garage at the track and started moving forward TC would shut me down before the car moved 10 ft. I just pushed the button until everything was off and never gave it another thought.
Enjoy your track time.
Bill
Thread Starter
Racer
Joined: Nov 2006
Posts: 448
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From: Dallas, TX
As long as you have your tire pressure sensors programmed correctly and they behave while on track all you have to do is turn off TC and you will be fine. If you want to run AH it will work since AH doesn't use wheel speeds to determine when to activate. AH activates based on steering angle, lateral Gs and yaw rate.
I ran a R888 setup that had slightly larger diameter tires in front than the rear and when I backed out of the garage at the track and started moving forward TC would shut me down before the car moved 10 ft. I just pushed the button until everything was off and never gave it another thought.
Enjoy your track time.
Bill
I ran a R888 setup that had slightly larger diameter tires in front than the rear and when I backed out of the garage at the track and started moving forward TC would shut me down before the car moved 10 ft. I just pushed the button until everything was off and never gave it another thought.
Enjoy your track time.
Bill
Thanks Bill!
Race Director
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From: Southern CA
I remember when one novice c5z guy was at my autox & had all kinds of brake issues on course. The codes made no sense, so I sent him to napa to get a new batt. Fixed everything & he bought me lunch.
Race Director
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From: Southern CA
Instructor
Joined: Nov 2004
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From: Santa Ana California
I totally agree with Bill, I run Nitto NT01 on my C6 (275x17/315x18) which are larger in the front than the back. Car has a fit with traction control on, it lets me know right away that its not happy. Pushing the button once will turn it off and the car drives fine. I usually hold down the button for 10 seconds to turn everything but ABS off for the track.
As long as you have your tire pressure sensors programmed correctly and they behave while on track all you have to do is turn off TC and you will be fine. If you want to run AH it will work since AH doesn't use wheel speeds to determine when to activate. AH activates based on steering angle, lateral Gs and yaw rate.
I ran a R888 setup that had slightly larger diameter tires in front than the rear and when I backed out of the garage at the track and started moving forward TC would shut me down before the car moved 10 ft. I just pushed the button until everything was off and never gave it another thought.
Enjoy your track time.
Bill
I ran a R888 setup that had slightly larger diameter tires in front than the rear and when I backed out of the garage at the track and started moving forward TC would shut me down before the car moved 10 ft. I just pushed the button until everything was off and never gave it another thought.
Enjoy your track time.
Bill
Le Mans Master
Joined: Aug 2000
Posts: 6,486
Likes: 1,658
From: Las Vegas NV
I'm interested in how ABS will NOT activate in error with such a setup (larger front tires than rear)?
ABS most certainly monitors and compares individual wheel speeds, and expects that the RPM for the front tires will be greater than the rears under normal braking due to the front's smaller diameter. If ABS sees that the fronts are turning *slower* under braking than the rears, it will reduce braking force to the front calipers to alleviate the (perceived) slippage/locking. That's how its designed to work.
I'm guessing the guys running larger fronts than rears have disabled ABS in addition to disabling AH/TC?
ABS most certainly monitors and compares individual wheel speeds, and expects that the RPM for the front tires will be greater than the rears under normal braking due to the front's smaller diameter. If ABS sees that the fronts are turning *slower* under braking than the rears, it will reduce braking force to the front calipers to alleviate the (perceived) slippage/locking. That's how its designed to work.
I'm guessing the guys running larger fronts than rears have disabled ABS in addition to disabling AH/TC?
Last edited by Kent1999; Mar 31, 2015 at 01:29 AM.
Burning Brakes
Joined: Oct 2013
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I just installed new rims and tires and running a square set up 18x10.5 rims with 275's
and my traction system active is coming on also above 50mph.
so too be clear, shutting it off does not effect ABS? thanks
and my traction system active is coming on also above 50mph.
so too be clear, shutting it off does not effect ABS? thanks
Le Mans Master
Joined: Aug 2000
Posts: 6,486
Likes: 1,658
From: Las Vegas NV
Both TCS and ABS depend on the correct tire diameter ratio, front-to-rear.
Last edited by Kent1999; Jun 7, 2015 at 05:23 PM.
Thread Starter
Racer
Joined: Nov 2006
Posts: 448
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From: Dallas, TX
With TC/AH turned off at the track, I did not experience any unusual braking behavior though I don't recall ABS kicking in throughout the day. Basically, I didn't have any issues with the setup.
Dan
Dan