Do not ignore VSC warning light at the track!

[snuff58]

Glad to see this thread. Before a third track session of the day (in August 2020) had ABS & Traction control warning lights come on. The Torque app reported no error codes. Checked fuses, but didn't leave them out. Missed the session, trying to figure it out. Restarting the car was no use. Eventually, the lights went off on their own. And haven't returned after many following track days.



2014
stock brakes
CSG Tein Flex A's
tight suspension
-3 7/8° front camber, -3° rear, Front 1/16" total toe out, rear 1/16" total toe in

[Evan55]

I had something similar happen at VIR this past weekend.
After hitting the gators coming out of oak tree the ABS light went on. No VSC warning light

The next lap, braking zone into T1, the right rear and right front locked up without much pedal pressure. Releasing the pedal did not immediately unlock the wheels. Flat spotted new RS-4s

ABS Light went off after turning off the car, and didnt have the problem again.

[ZDan]

Damn... So basically even if just the ABS light comes on, we should all be taking it SUPER EASY into the next braking zone! Damn haunted ABS/VSC....

I just pull the 40A fuse for tracking now. No matter what the computer *thinks*, it can't apply pressure to the brakes!
On the street, I haven't had any lights at all, and no weird braking behavior.

Originally Posted by Evan55

I had something similar happen at VIR this past weekend.
After hitting the gators coming out of oak tree the ABS light went on. No VSC warning light

The next lap, braking zone into T1, the right rear and right front locked up without much pedal pressure. Releasing the pedal did not immediately unlock the wheels. Flat spotted new RS-4s

ABS Light went off after turning off the car, and didnt have the problem again.

[rice_classic]

I wonder if there’s a correlation on brake fluid replacement intervals or if it’s solely an electronic issue.

edit: This only comes to mind because I know in some cars, brake fluid neglect causes premature failure or issues with ABS blocks.

[ZDan]

Originally Posted by rice_classic

I wonder if there’s a correlation on brake fluid replacement intervals or if it’s solely an electronic issue.
edit: This only comes to mind because I know in some cars, brake fluid neglect causes premature failure or issues with ABS blocks.

It's not the brake fluid... For one thing mine gets fully flushed once a year, and for another in my case there is a yaw sensor error involved, which I don't believe could be related to "bad" or old brake fluid.

[Turbo]

Originally Posted by ZDan

Alright, I'll do a suspension nut/bolt check and probably verify alignment before I go to NHMS.

Did you have massive front brake lockups?

Yes - I nuked my set of AR1s because of a massive front lock up as the systems we're talking about failed (and turned off) in the middle of a heavy braking zone.

[Turbo]

Originally Posted by ZDan

Damn... So basically even if just the ABS light comes on, we should all be taking it SUPER EASY into the next braking zone! Damn haunted ABS/VSC....

I just pull the 40A fuse for tracking now. No matter what the computer *thinks*, it can't apply pressure to the brakes!
On the street, I haven't had any lights at all, and no weird braking behavior.

Did you check all your suspension arm bolts? Rear wheels for play? Alignment specs?


Curious what you found out because in my situation it was pretty cut and dried.

[Devil 86]

Did you do a 2:14 on the continentals or the a7s?

[ZDan]

Originally Posted by Devil 86

Did you do a 2:14 on the continentals or the a7s?

A7s, 5 seconds slower on Contis.

[Dave-ROR]

Just had the same thing happen on my FRS in the braking zone for T7 (hairpin) at Sebring. Lights out after restarting the car. I dont think I have my good code reader here unfortunately. DESTROYED 2 basically new GY Supercar 3R tires too

On the plus side I'm ~3 seconds a lap faster with CSG spec SRCs than the Eibach R2s.. @CSG Mike

Going to be a total ***** next time out... I still have tomorrow day, tomorrow night and sunday day track time this weekend so pulling the f'ing ABS fuse if I have to.

On a sidenote the car WAS just aligned. THe steering wheel is offcenter slightly so I'm wondering if it needs to be centered through the toyota software (techstream?). I checked all suspension bolts (always do after alignments) this morning and all were snug. I will check them again.

[Pat]

Originally Posted by Dave-ROR

On the plus side I'm ~3 seconds a lap faster with CSG spec SRCs than the Eibach R2s.. @CSG Mike

Wow, that is a HUGE difference. Impressive.

[ZDan]

Originally Posted by Dave-ROR

Just had the same thing happen on my FRS in the braking zone for T7 (hairpin) at Sebring. Lights out after restarting the car. I dont think I have my good code reader here unfortunately. DESTROYED 2 basically new GY Supercar 3R tires too

Well dang... At least you didn't hit nuthin!

Front lockups I presume? Symmetrically or did one side lock up sooner/harder? That was how it worked for me... Fortunately I was on Conti ECS at the time and they're hard enough they didn't get badly flatspotted.

Going to be a total ***** next time out... I still have tomorrow day, tomorrow night and sunday day track time this weekend so pulling the f'ing ABS fuse if I have to.

I got the same behavior every time I went out, after maybe a lap or so the warning lights would come on and the fronts would be massively overclamped to lockup at the next braking zone.

I couldn't track the car safely until I pulled the fuse.

Next event at Palmer, first time out I forgot to pull fuse, so took it easy for a few laps then came in and pulled it. Unfortunately it was cool to cold ambient temps at Palmer and I had a couple of normal, controllable front lockups but flatspotted the bejeezus out of one of my A7s, had to TT on the Contis :'(

I felt like my CSG spec C2 front pads worked a lot better cold than my WinMax W5 rears, hence too much initial front bias => early front lockups. Wasn't a problem running sans ABS at Watkins Glen.

[Dave-ROR]

Originally Posted by ZDan

Well dang... At least you didn't hit nuthin!

Front lockups I presume? Symmetrically or did one side lock up sooner/harder? That was how it worked for me... Fortunately I was on Conti ECS at the time and they're hard enough they didn't get badly flatspotted.

I got the same behavior every time I went out, after maybe a lap or so the warning lights would come on and the fronts would be massively overclamped to lockup at the next braking zone.

I couldn't track the car safely until I pulled the fuse.

Next event at Palmer, first time out I forgot to pull fuse, so took it easy for a few laps then came in and pulled it. Unfortunately it was cool to cold ambient temps at Palmer and I had a couple of normal, controllable front lockups but flatspotted the bejeezus out of one of my A7s, had to TT on the Contis :'(

I felt like my CSG spec C2 front pads worked a lot better cold than my WinMax W5 rears, hence too much initial front bias => early front lockups. Wasn't a problem running sans ABS at Watkins Glen.

Just did some cruising laps (back to eibach laptimes lol) and it happened under throttle turn17.. acceleration went flat for a second like a fuel cut, looked at the cluster and witnessed them both light up then power came back. Took it super easy the next lap and brought it in.

Its throwing a steering angle circuit code every time it happens (turns out i did have my reader). I threw that clockspring in it from a wrecked car so I'm thinking its just damaged and getting worse... or that combined with the off center alignment is just enough to piss off the vsc system.

As for the lockup, front left, then front right, then both with the left leading a little. Breath on the brakes after they do it and they insta lock so i gave up on the tires lives to save the car instead.

[ZDan]

Originally Posted by Dave-ROR

Just did some cruising laps (back to eibach laptimes lol) and it happened under throttle turn17.. acceleration went flat for a second like a fuel cut, looked at the cluster and witnessed them both light up then power came back. Took it super easy the next lap and brought it in.

Its throwing a steering angle circuit code every time it happens (turns out i did have my reader). I threw that clockspring in it from a wrecked car so I'm thinking its just damaged and getting worse... or that combined with the off center alignment is just enough to piss off the vsc system.

As for the lockup, front left, then front right, then both with the left leading a little. Breath on the brakes after they do it and they insta lock so i gave up on the tires lives to save the car instead.

This sounds very similar to what I experienced. Insane asymmetric front lockups at brake pedal forces way below what should produce that even without ABS. Initial diagnosis with normal OBD-II reader diag was steering angle sensor but deep dive with laptop and diagnostic software showed "yaw sensor error".