ESP light - brake switch?

[5ktq]

A couple times now, my ESP (?) light (triangle with '!' in it and circle arrow around it) has come on steady. goes away when the car is restarted.

Only code I'm getting that would correlate is brake switch - intermittent.


Seems pretty slam dunk but just checking if that is likely the case, or if its the ABS unit itself?

When watching ABS measuring blocks and pressing / releasing brakes, the switch and the... redundant test switch? one of them seems to lag or stick on entirely, so that seems like it's probably the problem...

[J.kaseno]

I had that problem last year. My ESP was accompanied by CEL and another light but i forget. As stupid as it sounds, i replaced coil packs, plugs, and cleaned the throttle body chasing other issues and the problem went away. The stealership tried telling me my throttle body was bad and needed replacing along with a $3700 quote with a few other things found in their "inspection". My vehicle died on the side of the highway and idled very weird though. Ive learned these cars are finnicky af! Since, not a problem beside my current concrete ordeal.

People did point me towards a possible faulty break light switch at the time though. Id check that option out. Cant imagine it is that pricy.

Sent from my SAMSUNG-SM-G920A using Tapatalk

[f0reignfeatures]

A bad ABS module will throw an ESP light and your ebrake light will illuminate. It also gives off the distinct 2-3 beeps when you first start the car.

I swapped my brake switch since I didn't have VAGCOM and it was the easiest/cheapest thing to replace.

I still have my good one if you wanna buy it for cheap, just let me know. Good luck!

[5ktq]

PS I haven't noticed any funnyness like the brake lights being on when the car is off, but I'm sure it could be sticking here and there as i can't really see behind while im driving.

Drove by a broke down B6 on the freeway just now. rip

[coffeysm]

Same thing happens on my car it's very intermittent in my case though. I have a new brake switch, but havent put it in yet.

[eljay]

I am having a strange issue, not sure if it's related.
Randomly, when I accelerate under load my ESP light starts to flash and the power is cut. It's as if the brake is applied or gas supply cut. But it only happens under those conditions and I can almost replicate it reliably.
No fault codes, so I wonder what that is.

[5ktq]

Is a wheel slipping? like that's how it's acting? I'd guess either a wheel sensor or the inertial box thing, then..? hm.

I guess steering module could come into it too?

[eljay]

Is a wheel slipping? like that's how it's acting? I'd guess either a wheel sensor or the inertial box thing, then..? hm.

I guess steering module could come into it too?

Hmm, I would think that VCDS would show some codes for the steering wheel module.
Also, the fact that it happens only under load is interesting.
There's no wheel slipping.
I recently replaced one front wheel bearing. The speed sensor looked good visually and no codes for it. Is there a way to test it with VCDS?
I also noticed that my ESP button is quite sticky for some reason. I will replace it and see if that is the culprit for triggering it, but it makes no sense that it happens under those load conditions only.
I have a new brake switch in my parts stash, so I may throw that in, although I don't think that's the issue.

[Biged243]

Did you clean the pick up on the sensor off when you replaced the wheel bearing? It can get very dirty and pick up a bunch of metal flakes that can interfere with the read of the sensor. Just a small possibly.

[eljay]

Did you clean the pick up on the sensor off when you replaced the wheel bearing? It can get very dirty and pick up a bunch of metal flakes that can interfere with the read of the sensor. Just a small possibly.

I did and I cleaned the hub thoroughly, so I'm puzzled, but it may be something there, so I'll re-check my work now that I've put on a few hundred kms on it.

[old guy]

Hmm, I would think that VCDS would show some codes for the steering wheel module.
Also, the fact that it happens only under load is interesting.
There's no wheel slipping.
I recently replaced one front wheel bearing. The speed sensor looked good visually and no codes for it. Is there a way to test it with VCDS?
I also noticed that my ESP button is quite sticky for some reason. I will replace it and see if that is the culprit for triggering it, but it makes no sense that it happens under those load conditions only.
I have a new brake switch in my parts stash, so I may throw that in, although I don't think that's the issue.

Either replace the switch or reset the current one. If the ECM thinks you have depressed the brake pedal for more than three or four seconds along with a partially open throttle it will cut the throttle response and put the engine at idle. You can easily duplicate this by lightly touching the brake pedal while driving at a steady speed. After a few seconds the ESP light will come on and the throttle will cut.

Why only under acceleration? It could be that your switch is right on the edge and the acceleration places just enough pressure on the brake pedal to set it off. Kinda like when you accelerate you can feel it pressing you back slightly in the seat. The same force applies to everything else in the vehicle.

And yes you can use VCDS to test the wheel speed sensors: Clicky click

[eljay]

Either replace the switch or reset the current one. If the ECM thinks you have depressed the brake pedal for more than three or four seconds along with a partially open throttle it will cut the throttle response and put the engine at idle. You can easily duplicate this by lightly touching the brake pedal while driving at a steady speed. After a few seconds the ESP light will come on and the throttle will cut.

Why only under acceleration? It could be that your switch is right on the edge and the acceleration places just enough pressure on the brake pedal to set it off. Kinda like when you accelerate you can feel it pressing you back slightly in the seat. The same force applies to everything else in the vehicle.

And yes you can use VCDS to test the wheel speed sensors: Clicky click

Thank you!
I'll give a try since I already have the switch and seems to be a quick replacement.

It would make sense that it would move a bit under acceleration, but this happens when accelerating under load (high gear, low rpm), so the car is sluggish (not much of a g-force feeling) normally anyway and that's when this happens. If I accelerate swiftly with high rpm and really push myself into the seat, it doesn't happen.

I'll report back once I have a chance to install the brake switch and check speed sensors.

[MetalMan]

A couple times now, my ESP (?) light (triangle with '!' in it and circle arrow around it) has come on steady. goes away when the car is restarted.

Only code I'm getting that would correlate is brake switch - intermittent.


Seems pretty slam dunk but just checking if that is likely the case, or if its the ABS unit itself?

When watching ABS measuring blocks and pressing / releasing brakes, the switch and the... redundant test switch? one of them seems to lag or stick on entirely, so that seems like it's probably the problem...

I've had a similar issue, and think I recently fixed it: when sitting at a light, sometimes I'll have light brake pressure applied just to keep the car from rolling (manual trans). If I were to pay enough attention, I might notice that the brake lights aren't on, but the brake is definitely on slightly. Then the ABS/traction control lights would come on.

I believe my issue was an incorrectly set brake light switch. The ABS module's pressure sensor would sense brake pressure, but the brake switch wasn't telling it that the brakes were applied... so it would freak out and disable the system.

Simple fix: re-zero the brake switch, and reinstall paying careful attention to the plunger's engagement point. It took a few tries, including placing a temporary shim between plunger and pedal, before I got it perfect. Now the brake light comes on when there is brake pressure, and after 3 separate drives the issue hasn't come back. Mostly I was just really hoping to avoid spending $150+ on the ABS module brake pressure sensor