I was reading an article on AUDI forums about esp light on . It said could be the MAF sensor or brake light switch faulty but how could it affect the esp. (AUDI dealer quoted me 3000 euros to change the ABS module and i' been told before by an independant specialist that the MAF sensor is faulty as i don't trust the dealer since some other bad experience )

 

Run away from that dealer as fast as you can...they are seconds away from pulling a gun on you and killing you for your wallet & wristwatch.

Even if replacing a brand new ABS module at Audi part and labor price, it should be no more than 1500 euro (about $2000 U.S.)....actually less. The labor is NOT that involved.
Don't know what country you're in, but there are companies worldwide that test and/or rebuild abs modules at reasonable prices...BBA-Reman in UK, for instance...they will also evaluate modules for rebuild possibility. Also many similar companies sell rebuilt modules with lifetime warranty.

The MAF should not have anything to do with the ESP light...the brake light switch, as I understand, may be tied into that system, but don't know if it could trigger the light.

Unless you are made of money and can't be without the car for more than a day, GO TO AN INDEPENDENT GARAGE. They can hook an OBD-2 scanner to the car to confirm the MAF problem and should be able to confirm a brake light switch problem also (if it exists). If they have no OBD-2 scanning & coding capability, leave immediately...they are not qualified to work on your car.
A good mechanic at a good facility can find an ABS module for you, if that is what is needed (new, repaired or replace with reman module). The work to change it is not that involved for a good mechanic.

The price quoted by your Audi "stealer" is beyond all reason...that labor charge should be enough to swap a transmission.

 

P.S. Additional info:

After looking at BBA-Reman (just one of many companies), in many cases the electronic part of the module can be separated from the hydraulic unit and the car remain drivable in the interim...minus ABS and traction control functions.

http://www.bba-reman.com/content.asp....3_ABS_Removal

I've read this in countless other tech forums and rebuild company info also.

The major point being, the dealer automatically (in my experience) replaces the entire unit, electronic / hydraulic together and tells you incorrectly, that this is the only way it can be done...not true...thus a much higher price. The problem, if one exists, is almost always in the electronics.

I'm hoping that all this info will help you when talking to a qualified mechanic...NOT the Audi dealer. The more you know , the more respect you'll receive from the mechanic....and be a little less likely to get robbed.

Good luck.

 

Unfortunatley, the only way to get a new unit from Audi is the complete unit. Yes, I'm a tech at an Audi dealership btw. List price is $1,600. You are correct that the labor is not that much. If you take your time, to R&R the unit and pressure bleed the system will be an hours labor. Last one I did, we got a used assy from a salvage yard here for $400, and I think labor was $250 (2 hours@$125/hr) and that included diag time.

At the "Stealerships" we are in the same boat as the rest of you in that we don't have much control over the price of the parts, they are what they are, hence installing a used unit for 1/4th the price..............

Oh yeah, the brake light switch could cause the ESP light to come on. There's actually 2 switches in it. If the ABS doesn't "see" both activate at exactly the same time, AND below a certain brake fluid pressure (3.0bar or less) it will detect a fault and disable the ESP (and usually the ABS as well). The switch is a common failure item and is only about $12 (even at the "Stealership"!) and it takes roughly 10 minutes to install. At one point there was a campaign to replace the switches on certain years and models. The current switches are a revised design, and manufacturer if I understand correctly.

 

Thanks, aspen79.

First, I hope I didn't offend you as an obviously honorable employee and trained specialist. I picked up the "S" term from bad influences here on these forums
I don't think anyone here would badly prejudge a tech, just because they work at an Audi dealer. On the contrary, I highly value your views and information. It's kinda like working for the government....a lot of good/talented people AND a few (maybe a lot) of bad ones...depends on personal experience.

I envy those who have written words of praise for their local dealers. Unfortunately, in my area, there's only one Audi/Porsche/VW dealer (all-in-one) for many miles, so they have no competition and take full unethical advantage of that fact. In their case it's a problem from the management down...even their head techs are not only incompetent (multiple personal experiences), but equally unethical...seems like a virus or brainwashing. They also abuse the uninformed on a regular basis. I won't name the dealer at this point...could write pages about their reign of terror (they've had the monopoly for many years)....I'll save that for another time in a relevant thread.

Anyway, thanks so much for confirming a fair price for the ABS module switch, from an insiders point of view AND the information on the brake switches.
I hope you post on a regular basis and look forward to any further confirmations...or corrections, when I (or anyone) gets it wrong. I wanna know...I am far from an expert...just an enthusiast/shade tree mechanic.

 

I should also add, that the MAF sensor, just like the brake light switch, is tied into the brake electronics. I HAVE seen a bad MAF cause an ESP light, since it calculates engine load, the brake electronics also use it as an input. The brake light switch is the cheapest and easiest to replace, you can also diagnose it with a vag com but thats complicated and you have to know exactly what your looking at, i say just replace it. Then clean the MAF with MAF cleaner only! then clear the faults and see what comes back. The mechanic you're dealing with is not the sharpest tool in the shed i would imagine.

 

Read and learn.
Even though this is not my problem yet, I'm intrigued... I like to be forewarned for worst case scenarios.
I've just got the Bentley CD manual to study...also don't have VAG.com (will eventually...just a simple code reader now) so haven't delved deeply into that section except for codes I've found with my reader.
Bentley's component overview for ABS doesn't show the MAF as part of the system, but then again it doesn't show the ECM either. When reading deeply into the Vag.com section and wiring diagrams, I see the connection.
Thanks for your qualified input. Please keep it coming...I always wanna learn more...not to mention SCHIU, who DOES have the problem.

 

I've been told by the independant audi specialist today that they've tried a new maf sensor and the ESP light goes off. This part alone is going to cost 400 euros but i've managed to find cheaper from elsewhere. Good job i didn't listen to the dealer about the 3000euros ABS module. My car is having full service, brake fluid change, transmission fluid change , MOT and will be ready tomorrow. I am in HONG KONG and there is only one AUDI dealer and they can charge whatever they like , a full service cost 1000 euros( in hong kong dollars is 12000 ). The MAF sensor from the dealer is 700 euros ( parts only), every time i walk in to the dealer i have to expect a charge of over 1000 euros even an inital inspection is 80 euros per item ie if 10 items is 800 euros. My car was purchased in UK , as i originally resident in England. The car has TV function but somehow the TV icon disappear from the MMI . I did contact AUDI dealer in England and they advise to go to AUDI hong kong and have the car connected to Germany to reset the MMI . Obviously audi hk refuse and they keep on saying the TV tuner is malfunction and cost 2000 euros for the part. OK if there is a faulty tuner the TV icon should'nt disappear . The independant specialist has no idea how to fix this. Is there any other way to reset the MMI without begging the dealer .Could the MAF sensor be cleaned instead of getting a new one

 

Yes you can clean the MAF sensor with MAF sensor cleaner, it may not work though. As for re-setting the MMI there is a procedure for re-booting it by pushing 3 buttons, however i don't know what the three buttons are, it should be in your owner's manual or you can find it online.

Can't you get parts online shipped to Hong Kong? I know there are aftermarket part dealers for audi in the UK which has to be cheaper than getting hosed at the dealer.
Some of the US companies will ship overseas as well.