ABS/TCS and TPMS lights coming on.
 

EDIT: Fixed. See post #7 on this page.

I tried to be as concise as possible cause I can be pretty wordy! I also tried to write this in order of actual events as much as possible.

Installed 4th brake light a long time ago. Threw ABS/TCS when parking lights were on. Eventually I unplugged it. Figured out I was grounding it wrong, but left it disconnected anyway. Also had a LED flasher relay installed, but was pretty wonky on and off(sometimes the hazards stay on when car gets turned off and I can only turn car back on and off to get it to stop).

Got Advanced Keys push to start/keyless entry partially installed last year(It was functional enough). Installed auto headlight module/stalk recently. Works fine. Started working on keyless entry again recently to make it work how I want. Went ahead and hooked the 4th brake light back up. Working fine. Installed iDatalink bypass to get the car to use OEM beep when locking and unlocking. Also installed new LED flash relay to replace annoying old one. Then it started to throw the ABS/TCS as well as TPMS light. TPMS light flashes then stays on when I reach above 2500ish RPM until I put car in neutral then TPMS light is off.

Eliminated 4th brake light as a problem because at first the ABS/TCS only came on when the parking lights came on(first happened when going under overpass cause auto headlights) so I disconnected it. Disconnected it and no ABS/TCS when parking lights come on. But ABS/TCS still come on when I press the brake whether or not parking lights are on. Also put back wonky LED flasher relay, but same problem. After a ton of reading I figured the brake switch probably just needs to be replaced because it probably got fried from all the craziness of the brake light and other stuff happening.Also brake fuse is fine. One thread said something about TPMS coming on because of ABS/TCS error. Cause TPMS is definitely wrong. All tires pressure has been just fine. Filled them up anyway just to be sure and TPMS is still on so I feel confident all three lights are related.

Did I miss anything or does this all seem to make sense? Took me awhile to piece together what probably happened. I ordered a new brake switch from eBay, but if anyone has any other possible solutions I’m open to them. I read one thread about speed sensors being dirty, and while my car is pretty damn dirty, I just don't think that's what this is since I can repeat the issue by pressing the brake.

Just want to get this solved. Killed my dome light many moons ago when installing door step lights and recently figured out how to fix them(desolder/solder new chip in ECU) so I’m tired of weird/random craziness with this car.

If you read all this then thanks! Enjoy a hot cosplay girl:):
http://i.imgur.com/WLiBMuc.jpg?1

I'm glad I scrolled down after the first paragraph, but how am I supposed to read the rest now?


It seems like you are all over the place with additional electronics. I would revert as far back to stock, then start over. I even mean reinstalling the filament bulbs.

I also saw catgirl then.
TL DR

I mean I already ordered the new switch. I think if that doesn't do it then I'll slowly work backwards to see if I can pinpoint it, but I feel pretty good that it is the switch. Or at least I have to be hopeful it is. It was so frustrating that the dome light was burnt out for like a year until I stumbled upon a thread explaining the fix. And there were enough threads talking about the brake switch being an issue that it seems plausible that that's what happened here... I have a few days before it's supposed to arrive so was just hoping to see if anyone else had any thoughts on things I can try in the mean time. Without reverting EVERYTHING back. Cause that's a lot based on what I have done... haha :bonk:

And that is the exact reason why I don't mess with any wiring in the car.

I have this problem intermittently with no modifications to wiring or lights.
I shut off the car and it goes away.

I asked the dealership on the last service to clean the ABS sensors if any road debris was causing this trigger. Have not had an issue since.

Fixed it. Issue was the bypass module. As I was driving around today I really took note of the TPMS light and that it was actually basically coming on after I was in any gear for long enough time, but if I went into neutral, whether because of shifting or whatever that the light would "reset." This lead me to think of it being the tachometer. I double checked my wiring for the bypass module since it was the last thing installed and did in fact have a wire for the tach. I didn't have it wired. Wired it in and boom, no more ABS/TCS light or TPMS after a quick drive. It'll be for sure after a few days of driving, but I feel pretty good about this.

Thanks to everyone that read this and contributed any advice! :thanks: Enjoy another hot cosplay girl!:
http://i.imgur.com/wyy2dz2.jpg?1