Traction Control/ABS Issues at Thunderbolt

Discussion in 'Corner Carver Racing Tech Discussion' started by Stanger11, Sep 15, 2020.

  1. Stanger11

    Stanger11 Junior Member

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    I have a 2013 Mustang Track Pack with a Bama tune and was experiencing my front driver side brake “locking up” as I was both entering and exiting corners at Thunderbolt today. It happened nearly 25 times each lap I made (I only ran a few laps as it was too bad to continue). My instructor was also telling me the brake lights were flashing 3 times through the corner even though I was not applying the brakes. Has anyone ever experienced this? I thought it was a ABS sensor at first but think it may be the tune now.
     
  2. RavenGT

    RavenGT Member

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    It wouldn't be the tune.
     
  3. ddd4114

    ddd4114 forum member

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    Are you leaving stability control on? That can definitely make it feel like the brakes are randomly engaging (because they are). However, I'd be surprised if the brake lights also turn on. I guess it's possible but I've never been told either way if that's true.

    As mentioned, the tune seems highly unlikely to cause this. If you're off the brake pedal, a wheel-speed sensor seems highly unlikely as well unless you're leaving stability control turned on.
     
  4. Juice

    Juice forum member

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    Which brake light? Dash or on the rear?

    One front wheel locking up would indicate a fault at that wheel. Either a sensor/tone wheel issue or an ABS module issue.
    You need to scan the ABS module for codes.
    If you dont have codes, view live data of all 4 wheel speed sensors and see if those show the same reading for all wheels.

    Time to break out rhe scan tool.
     
  5. Norm Peterson

    Norm Peterson corner barstool sitter

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    If an ABS sensor had gone bad, the ABS system is supposed to take itself offline, which should take everything that's piggybacked on it down as well. Not sure how a sensor in the process of going bad - I'm thinking some sort of intermittent issue here - might be treated, though.

    The only thing that makes sense to me where you'd be getting front brake activity on corner exit would be if AdvanceTrac was on and was sensing oversteer. I suppose it's possible that A-T turned itself back on; I've heard that a straight line ABS event can cause that to happen, at least with some stability control systems.

    Which corners was this happening at? Was it happening at T5 or T10 at all?

    It's a little late now, but I think I'd have physically disconnected an ABS sensor between sessions, at least for diagnostic purposes.



    Norm
     
  6. Juice

    Juice forum member

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    I have seen abs sensors drop to 0 mph from say 30 mph and funkiness happen and not set a code..... Yet.
     
  7. Stanger11

    Stanger11 Junior Member

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    Thank you for the feedback and responses.

    There were no lights on the Dash other than one time where the traction control light flashed for a split second. The brakes lights were flashing on the rear of the car when the instructor was following behind me even though I was not "on" the brakes.

    This issue occurred at every turn on the course even left handers (T5).

    I am visually inspecting the car this afternoon to see if there is anything noticeably wrong.
     
  8. Stanger11

    Stanger11 Junior Member

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    In addition, I was turning the "AdvanceTrac" system on and off while driving around the course and it made NO change to the brake issue I was experiencing. I have "tracked" the car at LimeRock and Palmer Motorsport Park this summer and did not experience this problem (and I left the "AdvanceTrac" on at both track events and did NOT experience this braking issue). I have felt the effects of the "AdvanceTrac" losing traction but this time it felt different at the track.

    Also, I had the brake fluid flushed after the LimeRock and Palmer events and before the NJMP event and the front tires re-balanced. In addition, I had to put on a "friendly emissions" tune after LimeRock/Palmer in order to get the car through Pennsylvania emissions last week at which time I re-installed the 93 "Race" tune. I'm just trying to point out changes to the car since the different track events.
     
  9. WJBertrand

    WJBertrand forum member

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    Could a bad wheel bearing cause spurious signals?


    Sent from my iPhone using Tapatalk Pro
     
  10. ddd4114

    ddd4114 forum member

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    Just to be sure we're understanding your problem correctly:
    - Have you ONLY had this issue in corners at Thunderbolt?
    - I assume this car is still street-driven? If so, did you have this issue at all before or after going to the track?
    - When you say you turned AdvanceTrac on and off while on track, were you just turning off traction control (pressing the button once) or putting it in Sport Mode (pressing the button twice)? I assume you weren't stopping in the pits and completely turning it off. If you were just turning off traction control, I doubt you'd notice much difference if you were just pushing the car in corners.
    - Why did you have the front tires balanced before going to this event?

    If you saw the traction control light flash at all, it seems pretty likely that the stability control system is intervening. The most obvious causes are a bad wheel speed sensor, a wheel that's horribly out-of-balance/damaged, or driving more aggressively than you might have thought.
     
  11. Stanger11

    Stanger11 Junior Member

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    I did not experience this issue on the street prior to the track day event. I encountered the issue even during a warm-up lap so i dont believe i was pushing the car too hard (i drove it significantly more aggressive at Lime Rock and Palmer earlier in the year). I had the front tires re-balanced just to ensure they were balanced while i was getting new tires installed (i did not suspect the tires were out of balance).

    I was simply pressing the button on and off while I was on track to determine if it was the traction control causing the issue.

    After the event I have experienced this issue on the street as well although it's difficult to make it happen on the streets.
     
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