Esp malfunction
 

My AUDI A8 2003 (D3) Esp warning light is on continuously , what could be wrong . Please help

Could that be be "EPC" ... or possibly "ESP".
Not familiar with "EPS"...at least, not on a D2 (?)

I'm guessing ESP. Hate to ask the obvious, but you didn't hit the ESP button accidentally?

Good question...and the best possible scenario.

If it's "EPC" (electronic power control), the engine "should" be in limp mode (very low power) according to Audi Owner Manual, triggered by the engine control module, because it detected a problem with the electronic throttle control. Even if it's not in limp mode, "EPC" still indicates a detected problem there, unless the ECM is sending a false signal for some other reason...ECM problem, sensor, wiring, etc..
Other owners have said they've gotten this light and limp mode, but has gone away after restarting the car.

P.S. Isn't a 2003 model A8 still a D2 ? I'm just going by Bentley info...they don't show a mid-year change, but I've seen another source that said D3's started late in the 2003 model production (?). Just curious.

Well, being the ESP light (saw your correction), if you haven't turned it off with the dash switch and the light is staying on, you very well may not have anti-lock brake function either (plus no traction control or stability functions).

If the anti-lock module fails (electronic/hydraulic block under hood with brake lines connected), this ESP light will stay on....the two systems are dependent on each other (ABS and ESP). With a failed module, the ABS light will not necessarily turn on also.

If you turn off the ESP, the anti-lock brakes WILL continue to function, but NOT the stability control or traction control...IF all is normal.

If the ESP light is staying on by itself, you can test your brakes by hittin em hard in gravel or wet surface...if you skid, the ABS module may have failed. If anti-lock IS working, the problem is elsewhere in the ESP system (?).

Curious to hear an update, when you know anything.

The ABS module is a good posibility, the A4 and A6 suffers from this problem quite frequently, however never have i come across this on an A8. I would be looking at the wheel speed sensors for debris or damage before condeming the module. The reluctor rings could also be damaged, have you had your CV boots replaced recently?

Thanks for all your reply. I ' been told by the independant Audi specialist today that the ABS computer is faulty and it costs adout 1000 euros to fix. My car is a MARCH 2003 D3 model , and the mechanics said he will contact Audi dealer to see if i can claim goodwill warranty as some parts are covered for 6-7 years. Apart from that he said the oxygen sensor and the maf sensor are malfunction (what are they, is it necessary to replace them)

Ouch, thats a tough break mate. If thats what causing it make sure to get that warranty and never lose that piece of paper!

The oxygen sensor monitors oxygen in the exhaust system, primarily to calculate the fuel ratio when the engine is warm or more commonly called closed loop. This only applies to the before cat O2 sensor, the after cat O2 sensor just checks the functionality of the cat coverter itself. It won't affect engine performance, but will cause you to fail emmissions tests. (not sure what the europe standard is though)

The MAF (mass air flow) sensor does the same thing as the O2 sensor essentially when the engine is cold, it also does the job of calculating engine load as well as many other inputs that im not gonna get into. If the mechanic is sure both of these are bad i would recommend replacing them.

" I ' been told by the independent Audi specialist today that the ABS computer is faulty and it costs about 1000 euros to fix." --SCHIU

CAUTION : THIS IS NOT ADVICE for SCHIU !!
I lack the expertise to offer that in this case...especially if you can get it done under warranty, are not a mechanic, do not have a good friend who's a very competent mechanic AND can't let the car be disabled for a period of time...AND cost is not a "crippling" problem.

It's more a question and subject of discussion for AUDITECH79 and others with knowledge of this problem (and it's gonna be a "novel"):

I'm assuming, from the cost quote and description, that we're talking about (SHCIU's "ABS computer") our aforementioned ABS Module...please tell me if I'm wrong. On that assumption (and regardless), I'll start with a short story:

Years back, my wife's 2000 Passat GLX V6 (FWD) had an ABS module failure. I was heavily involved in another project at the time and did not give the problem my personal attention, which it deserved... AND I hate myself and regret not researching it to this day. It was out of warranty and cost her around $1500. All I did was give the Audi dealer a hard time about the cost and they swore the problem couldn't be anything else AND these modules couldn't be repaired by ANYONE! My wife told me to drop it, she wanted to pay the money and be done with it. I let it go and got back to my own project.

If I ever have a similar failure, I'll be taking another route, after all the reading I did later...and was ashamed for not checking into it deeper. One forum that has discussed this problem for years is this one:

http://tech.bentleypublishers.com/th...art=0&tstart=0

It's a B5 forum and is now 32 pages long, full of personal experiences, repair suggestions and a LOT of companies that have repaired these modules successfully...admittedly, a few of the repaired (or replaced) module owners reported "coding" problems after the fact (over my head at this point)...BUT most of these people in this and other (mostly B5) forums have reported great success with rebuilds in the $100-200 range (rebuild only) and a few with successful self-repairs of these supposedly "un-repairable modules".

As it was pointed out by AUDITECH79, this seems to be a real sore spot with B5 (A4, Passat, etc...) and the only source where I have luck finding info IS indeed in B5 forums, including the one here, which touches on repair rather than replacement.

My "question-observation-future fear" is the following...but I'll start with a list of module numbers that the Bentley forum (from their survey) concluded were among the most likely to fail...and prepare to have something new to worry about :) :

" The following documented vehicle modules are experiencing high failure rates:
8E0614111A, 8E0614111E
8E0614111B, 8E0614111F
8E0614111AH, 8E0614111AJ
8E0614111AA, 8E0614111T
8E0614111P, 8E0614111Q 8E0614111D
8E0614111R, 8E0614111S
8E0614111M, 8E0614111N 8E0614111C "

My wife's module was the 8E0614111A. The one presently in my '01 A8 is the 8E0614111T (listed above !!!). When I cross-referenced this number (including the Bosch # on the unit), I found that exact module is used in a plethora of other AWD models, including AWD B5, C's (A6) in many year models...back as far as '94.
When you visually inspect modules from ALL the numbers above, they are all identical in physical appearance, just a different ending letter depending on the model VW or Audi used in (and AWD or FWD).

If it happens to me again, AND THIS IS NOT NECESSARILY ADVICE FOR ANYONE ELSE, my first move will be to check out the list of companies that repair these modules...and, of course, other components in the system which might trigger the warning.

As always, Any and ALL thoughts on this subject welcomed.

Thanks.

^^^ Yes this information is all correct, the company most familliar with audi ABS (bosch) units is modulemasters, there are many other companies that can rebuild these modules as they aren't much different than any other ABS systems availaibe on the market. If the A8 does indeed have a bad module, modulemasters can probably repair it, however i doubt they have had too many sent to them. The engineers spared no expense when designing the A8, and almost every module/wire in that car is state of the art.