abs, tc, airbag and sai light all on and off

biped · Jun 28, 2016

15 tsi

i am lowered

this morning all of the above lights showed up at once. if i turn the car off and on again, they will re illuminate one by one.

quick search reveals nothing too jetta specific here.

thoughts? things i should be looking for? bad speed sensors? abs module?

vdubsurfer · Jun 28, 2016

Battery or alternator going bad... is my guess. Check battery and voltage output.

biped · Jun 28, 2016

checked both battery and alternator. battery resting charge is fine and it jumps up when the car is started. so the alt is charging.

no stored dtcs, but, i don't have vag either.

only thing i did differently recently is install new wheels.

car drives fine. lights up as soon as i start it, so i hesitate to believe it is a speed sensor.

vdubsurfer · Jun 28, 2016

that is odd... did you check the fuses (next to battery)?

xFlinstone · Jun 28, 2016

My '13 GLI did this a while back. It drove fine and all the lights went away after a couple miles. Not sure what caused it, it was pretty cold and I had gotten a tune a couple days before. Hopefully yours go away too

koidragon1980 · Jun 28, 2016

I'd try disconnecting the battery for about 20 mins to reset the ecu, then start it up and reset the tpms (it runs via the ABS module).

If that doesn't stop them from coming back, then the next thing I'd do is visually inspect each corner for any obvious signs of an issue (i.e. damaged sensor wires or disconnected sensors, etc.)

You'll also need to get a good VAGCOM scan. Not all issues/codes are able to be read via a standard obd2 scanner. Things like ABS, airbags, etc, are logged and stored separately and can only be read and cleared via VAG.

koidragon1980 · Jun 28, 2016

biped said:
checked both battery and alternator. battery resting charge is fine and it jumps up when the car is started. so the alt is charging.

no stored dtcs, but, i don't have vag either.

only thing i did differently recently is install new wheels.

car drives fine. lights up as soon as i start it, so i hesitate to believe it is a speed sensor.

Not sure if these cars run checks at start up but I had a Saab with faulty wiring running to a speed sensor. It would discover the voltage issue at startup and throw a warning. Intermittent issues would a code during movement, but if it looks for a signal at startup and no signal is present, it automatically throws a warning. This is why I would visually inspect the wiring to each wheel to check for any signs of wear or damage.

biped · Jun 28, 2016

thanks for the replies

couple things : i do not have tpms on this car, so that's a non issue. i have not checked the fuses either.

i took it for a drive today and the lights stay on. however on occasion the airbag light will go out or the sai light will go out, but they will both come back on.

weird..

i do have an appointment at vw but i may visually check things myself since i don't want a tech handling expensive fully polished wheels if they don't have to.

also i am fairly certain it is not speed sensor related since you can do the emissions trick and remove traction control while stopped but once the speed sensors pick up on the vehicle rolling, it disables it.

however any and all advice is still appreciated. car continues to drive fine. i could try resetting the battery i guess.

koidragon1980 · Jun 29, 2016

biped said:
...i do not have tpms on this car, so that's a non issue....

I'm fairly certain that the tpms system is part of the standard suite of safety feature systems that all 2015 Jettas come with. It's not a system that uses the sensor in the wheels like others do. Instead it uses the ABS sensors to detect certain parameters.

https://carmanuals2.com/volkswagen/jetta-2015-tire-pressure-monitoring-system-36438

It's probably not your issue, but it does involve the ABS module/sensors, and you should at least be aware that it is a system that exists on your car.

biped · Jun 29, 2016

so let me run this by you..

vw just called and said the reason my dash is lit up is because i am running two different tire sizes and the sensors are detecting differing revolutions.

i am low on staggered mercs, 8.5 n 9.5 with a 215/225 40

the size difference is ~1%

i told them to try again. there is no way in hell that this would cause this much to light up. not to mention if you put a donut on the car, this means you lose abs and airbags.

that answer makes no sense.

and i am honestly not sure about the tpms but i recently had a flat and absolutely nothing was illuminated so if in reality this car has tpms, it does nothing and indicated nothing therefore i feel it does not have it.

Gbells124 · Jun 30, 2016

i thought all the jettas had the tpms sensors that are read through the speed sensors and tone rings? if you have the actual in wheel tpms sensors than disregard this comment, but if it is the same as the gli you should check your abs tone ring, the little magnetic ring the speed sensors read to get tire pressure, speed, and abs. a small crack or piece falling off of the tone ring would cause all of these symptoms. i had my rear left tone ring crack and i had all of the same lights and got a left rear speed sensor code. had to replace the whole wheel/hub bearing but it was very simple.

Gbells124 · Jun 30, 2016

re read your original post and all the comments, and m fairly certain if its not the actual speed sensor it is the tone ring. get the codes read so you know which corner to look at, and then check the tone ring from behind the rotor and knuckle, and spin the wheel bearing so you can see the whole tone ring go around, cuz a tiny crack could cause this. if it looks perfectly smooth clean it off, and pull the speed sensor, clean that also, clear codes, if they come back you have a failed sensor and you just gotta replace it and clear them again. its super easy and you can get them cheap if you buy online. go on ecs they have everything you'd need. if you need more help pm me and ill walk you through it.

koidragon1980 · Jun 30, 2016

biped said:
so let me run this by you..

vw just called and said the reason my dash is lit up is because i am running two different tire sizes and the sensors are detecting differing revolutions.

i am low on staggered mercs, 8.5 n 9.5 with a 215/225 40

the size difference is ~1%

i told them to try again. there is no way in hell that this would cause this much to light up. not to mention if you put a donut on the car, this means you lose abs and airbags.

that answer makes no sense.

and i am honestly not sure about the tpms but i recently had a flat and absolutely nothing was illuminated so if in reality this car has tpms, it does nothing and indicated nothing therefore i feel it does not have it.

you have tpms. the reason that you probably didn't get any warning when you had a flat was because it doesn't actually monitor tire pressure like sensors in the wheels do. it takes wheel speed measurements at each wheel along with some other bits of data and if it detects something "off" then it will throw the tpms light. My 2015 SE did it to me the day I drove it home. I bought it used and the genius techs at the dealer put the front tires at 30psi and the rear tires at 40psi. It didn't throw it on right away, but over the course of driving about 10+ miles away from the lot, the system recognized the differences and threw a tpms warning. I put all to 36psi per the door sticker, reset the tpms, and all has been good since.

check your glove box. if you have a tpms reset button in there, then you have tpms. I'm fairly certain that you have it, but I doubt that running staggered is causing your issue... although to be honest, aside from looks, you get no real benefit from running a wider wheel on the rear tires of a front-wheel drive car. I guess it's possible, but I don't think it would light your dash up like a Christmas tree. I'd think it would just throw a tpms warning.

I'd lean more towards what Gbells said... a sensor or the tone ring, and then I'd highly consider going with the same width wheels all around unless you really need the scene points.

Also, what is an "sai" warning? Never even seen or heard of that one. If that's in reference to "secondary air intake" then that's a separate issue from abs, etc. but that doesn't have it's own warning lamp. SAI issues will throw a DTC and light up the check engine warning.

biped · Jun 30, 2016

sorry i just meant steering angle and mucked up the abbrev.

i am refusing to do any of the legwork here because my car is under warranty.

but volkswagen doesn't believe me whatsoever about the staggered width in sizes not causing this, and they are taking the easy way out and blaming the mods. so now i must return to the dealer on a square set of wheels and have them reset the codes then drive again so they will pop on.

i drove for six days and over 500 km with the mercs on before any of this happened. they just shrugged.

i am well aware there is no benefit to staggered wheels and tires. it is 100% for looks.

they are blaming it on a minute difference in rollout between front and rear.

scene points notwithstanding, that is not the issue. this small a difference should not cause the freakout.

i also, absolutely, 100% do not have a tpms reset button in the glovebox. i am telling you, canadian models are different and tpms may not be mandated.

abaron · Jun 30, 2016

biped said:
sorry i just meant steering angle and mucked up the abbrev.

i am refusing to do any of the legwork here because my car is under warranty.

but volkswagen doesn't believe me whatsoever about the staggered width in sizes not causing this, and they are taking the easy way out and blaming the mods. so now i must return to the dealer on a square set of wheels and have them reset the codes then drive again so they will pop on.

i drove for six days and over 500 km with the mercs on before any of this happened. they just shrugged.

i am well aware there is no benefit to staggered wheels and tires. it is 100% for looks.

they are blaming it on a minute difference in rollout between front and rear.

scene points notwithstanding, that is not the issue. this small a difference should not cause the freakout.

i also, absolutely, 100% do not have a tpms reset button in the glovebox. i am telling you, canadian models are different and tpms may not be mandated.

If you're in Canada you do not have TPMS (unless you enabled it with VCDS, but then you'd know that).

It's quite easy for them to "prove" that the staggered wheel setup is the problem; have them reset the system, throw a set of wheels from another vehicle (your courtesy car, for example) on and drive it for a bit. If the lights stay off, there you go. The could even move your wheels to a different vehicle as a control test.

abs, tc, airbag and sai light all on and off

biped

vdubsurfer

biped

vdubsurfer

xFlinstone

koidragon1980

koidragon1980

biped

koidragon1980

biped

Gbells124

Gbells124

koidragon1980

biped

abaron

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