mustangkiller01

Hello all,

I'm trying to diagnose my issues with the VSA triangle light always being on. the ABS light also flashes on every now and then when I hit a bump or go WOT. Usually that stays on until I cycle the key. But the triangle light always stays on. I tried the 4 and 9 pin reset but it didn't clear it. rather the abs light flashed its codes. Since my OBD2 scanner won't pull codes, I decided to go down the street quick to autozone and see if there's would. They said it would pull abs codes. Assuming i can trust what that scanner pulled, it showed a 24-1 Brake Pedal Stroke Sensor Malfunction and 84-1 Sensor 0 Position not right.

Is it possible these issue are caused by the brake pedal sensor? Does it seem likely that all these things are tied to that or do these codes and symptoms point to something else? I guess it's easy enough to replace that sensor and try to do the reset again, I did lots of googling and thread reading on here and didn't find too much that mirrored what i'm experiencing. I just thought I'd ask before trying out replacing that sensor or going to the dealer. Thanks!!

Chuck S

The VSA and ABS systems work together and there apparently a brake or wheel sensor problem. Any wheel or tire changes recently? Run over any curbs?

Download the Service Manual and go thru the section starting on Page 19-68.
There's about sixty (60) pages in that section which has much more information than can be put in a forum note.

-- Chuck

mustangkiller01

Thank you! This has been on since I bought the car. I'm just finally getting around to addressing. I did notice last night that the brake master cylinder was leaking. I wiped off the drip and took this picture... there's some discoloration on the carpet so it must have been doin it for a little while but it's so far up the footwell I didn't notice. I was going to flush and change the fluid and grease the slave cylinder and fork this Friday anyway since the clutch pedal started to noticeably squeak. I ordered a new brake master cylinder right away. I'm now wondering if this plays a role in these codes or if it's just a separate issue. Thanks again!!

Billman250

Rule of thumb, troubleshoot CEL codes first. CEL is an automatic VSA light.

mustangkiller01

Good to know! the car was throwing a CEL for P0139. I assumed this was because the car had a test pipe on it when I bought it (would love to get rid of this). I installed the angled spacer and cleared the code with my cheap scanner. That was probably 300 miles ago. No CEL light on right now, but i'm not sure the issues is solved completely...

Chuck S

P0139 is an emissions fault unrelated to the ABS and VSA.

Is the car tuned? Only reason I can think of for a "test pipe." Irresponsible regardless.

-- Chuck

mustangkiller01

The car is not tuned to my knowledge. It has a test pipe, UK mod to the factory exhaust, and k&n intake from what I could tell and what was told to me by the seller. I replaced the K&N with an OEM intake box and I'm currently looking to replace the test pipe if I can find a catalytic converter. The goal was to get this car 99% back to factory.

Chuck S

Just wondering if the ECU had been messed with. OE cats appear on Ebay from time to time and less commonly here. Aftermarket high flow cat will bolt right in the system.

Run thru the Service Manual. Just throwing random parts at a problem often doesn't work. There are sensors at each wheel used by those systems: one or more or none could be bad for example. I think the brake sensor merely warns of low brake fluid.

Our favorite S2000 guru is on Long Island (maybe 1/2 day away) and worth the effort.

-- Chuck

mustangkiller01

Thanks Chuck- I've been keeping my eye out for an OEM cat. I plan on reading through the manual since the last time I owned a s2000 it was back in 08 and my AP1 was low miles... these issues were never there so i'll have to catch myself up to speed. Thanks for the resources!

Chuck S

These are uncommon issues among those posting here. Loose or frayed wire to a sensor could intuitively case the issue. Bad controller "box" for either could as well as printed circuits can crack or have cold joints. The information that the former owner buggered the exhaust and emissions controls would make me want to check the car closer. Is the car lowered? OE spec wheels and tires?

-- Chuck