2001 Audi TT 225 hp engine, CEL, ABS, ESP lights all on and a strange sound


That adapter comes in different flavors…I have one for my long gone Tdi VW…it wont work on my GTi…so watch carefully what you buy.

I’ll be careful!

All the ones I find online are listed as VW specific, but I guess I’ll just see.

Like I said anyway, I’m going the multimeter route to begin with so the question may be moot with regards to the Vag Com. That will be more of a last resort.

Anyway, I have some eating, then testing to do and I’ll post back. I fully expect to at least know what needs fixing before this weekend is up.

I always forget to mention also, that my other main squeeze in life is fixing electronics. So I’m wondering if a part of the system is damaged if it wouldn’t be outside my ability to repair it.

Just go on Ebay …they will sell you the right adapter specific for your vehicle…then you just add your Software…from Vag Com…

The “sucking sound” is probably the waste gate on your turbo and is completely normal if that’s what it is. When you abruptly lift off the gas, the turbo has to dump all the excess pressure in the intake system.

The ABS and ‘anti-skid’ are likely manifestations of the same issue. It could be a bad wheel sensor. The ABS/stability control system needs to know accurately how fast all the wheels are turning in relation to each other to detect a wheel lockup and to use the system to mitigate a skid.

Your analysis of the CEL is probably correct—it could be any of these things… or something else… The key to accurately diagnosing it is to monitor data from the oxygen sensor(s) in real time with a scan tool. This will reveal if you have a bad or lazy sensor or at least point you in the right direction for further troubleshooting. Or if the sensor’s never been changed, it’s probably due anyway. Though throwing parts at it is an expensive way to troubleshoot a problem. Of course an inspection of the vacuum lines under the hood is a good start too. And so is having the fuel pressure checked. Typically if you have low fuel pressure, you will notice the engine bogging or losing power at higher RPMs as the pressure drops and the fuel pump can’t keep pace with the demands of the engine. A clogged fuel filter can cause this too, and I would change that first. A partially clogged fuel filter will give the right pressure under idle and low RPMs, but you won’t get the needed fuel volume at higher RPMs and the pressure will drop. A weak fuel pump can do this too of course.

Be sure to use full-synthetic oil in your turbo vehicle as well for maximum protection. Your manual likely calls for it.

Yo @oblivion: thanks for the detailed info but make sure you check the recent info on the post. The vac line leak was found and fixed ending the CEL issue.

The ABS ESP issues persist though, and I’m out working on it at the moment.

If you or any other sage have any ideas, throw em at me, I’ve outlined my approach above.

Thanks again everyone.

Only thing that comes to mind is prob what you already know…if any wheel sensor cannot see that ring…or any piece of that ring…then it thinks the wheel is either locked up while the others are turning…or is locking up…while the others are moving… Good thing to at the very least clean all of those magnetic sensors at each wheel.

Ok, a “little” progress. Per the Audi Service manual, the fault must be in one of the wheel speed sensors. I’ll be checking those out tomorrow.

So much for testing at the ABS module.

Damnit Audi, why did you have to make everything so difficult?

After removing the air box I noticed there is still some sort of black plastic box, I think it serves as a conduit, that blocks access to the cable leading to the ABS control module. So I’m down to jacking up each wheel to test individually, or finding someone with the vag com cable that I’m against buying because I don’t plan on keeping this car any longer. Oh well. Looks like I might be able to cut the wheels hard right and left to remove the front two, but that doesn’t really help me inspect the tone ring, but then again since it’s steady on I think the fault is at the sensor. Must be covered in crap or something. Would be nice if I had worked on only one recently, but I’ve been in each wheel well extensively at about the time this came on. The front driver side wheel well is really the only one I feel like I can ignore. Or save till last.

Here we go to suck-ville. Population me.

Hey again folks! Weather got really nice today so I took the opportunity to sort my wheel speed sensor situation. It’s the rear passenger side wheel speed sensor.

So, here’s the question. I am a man most handy with electronics, (I sit next to my infrared rework station as I write this) so is there a way to fix this sensor?

It reads as an open circuit. No resistance, no connection at all, so I’m thinking I’m dealing with something that can’t simply be cleaned up, but can it be fixed up. My understanding is that it’s a fairly simple sensor that operates like a little generator as the teeth of the tone ring pass it. What do you think I’m looking at here? I don’t know if I can re-wrap the copper wire, I’d guess not but maybe.

Anyway, let me know what you think.

Additionally, I’m having issues finding a write up on removal. Looks like maybe the entire hub needs to be removed to get to this little bastard, but if someone has done it on this platform let me know what I’m getting into.

Thanks again everyone.

Just go online an BUY ONE CHEAP…they aren’t cost prohibitive. Ebay “Buy it Now” anywhere from $20 ish up to $99…FORGET fixing it…its a disposable part


Oh, never mind on the hub removal. I just re-read the thread I was looking at for that. Looks like it might be a pain to get out, but it’s one bolt nonetheless.

@Blackbird: I think you’re right. I did find it for 32 somewhere. Maybe I’m getting a little to cheap. Just enjoy fixing electronics. From what I read about it my chances of removing it without destroying completely are pretty slim to begin with.