ABS - Kontrollleuchte geht bei über 20km/h an | Posts 16+

Well then .

Quote:

Apparently, a tiny layer of corrosion on the contacts was enough to prevent the current from flowing through the fuse when the pump started, and the control unit recognized this as a defective pump.

Absolutely correct. The measurement is at a high impedance, so nothing is being dropped, but under load, the transition resistance becomes fully effective.

The strip fuses (usually 30A or 50A) are screwed in, meaning they consist of a thin strip of metal that is fixed at both ends with a cross-head screw. You can find them, for example, in Plexiglas housings in the engine compartment or in the distribution box above the battery. In the G III, it was a box located on the strut tower. Due to their exposed location in the engine compartment, they tend to corrode, which can then cause difficult-to-locate faults.

Adding an entry to the database would probably be a good idea.
As an author, can you do that directly, or what is the usual procedure?

Okay, in my Bora, the fuses are plug-in fuses located above the battery. In my case, it was a 30A fuse that triggered the error; when facing the car, it was the leftmost of the three available plug-in fuses. I'm still incredibly happy that the error is finally fixed and that it was so cost-effective .

Best regards, Günni.

Roger wrote:

As an author, can you do that directly, or what is the usual procedure for that?

Okay, first write it as an "article by the authors," and then move it to the relevant, generally readable forum.

Hello!

First of all, it's great that the error has been found!

After remembering the same problem I had with my old 98 Golf, I also realized that, in my opinion, a reset of the ABS control unit was necessary.

The fuse located above the battery is either the ABS fuse for the pumps (labeled Kl.30) or the fuse for the valve supply; otherwise, to the best of my knowledge, there is only one other fuse, labeled Kl.15.
As Günni described, the error reappeared after each clearing of the error memory and after each drive. Given that I suspect there were trips without ABS intervention (during which a voltage drop in the power circuits could have been diagnosed), I believe that a reset of the ABS control unit was necessary to completely clear the error. This could be achieved by removing the two fuses (or perhaps only one), or alternatively, by disconnecting the battery.
Removing the fuses, of course, has the positive side effect of actually fixing the problem (=> eliminating contact resistances).
Or should the ABS-SG perform a diagnosis without any (noticeable) ABS pump or valve intervention, but with a higher load current?


Greetings.

Hello!
I'm also having problems with the ABS in my A3.
The ABS light initially only illuminated intermittently. After turning the ignition on and off, the error no longer appeared.
I had the error codes read at the workshop, and this revealed the diagnosis mentioned above.
After that, I had Abs checked.
This indicated that the pump occasionally 'gets stuck'. Replacing it is supposed to cost between €1100 and €1500 ( !!!!!!!!!!!).
I've postponed the repair for now. I received the advice to use the ABS frequently / to trigger it often. However, that didn't help.
Initially, the light would turn on at 20 km/h. Now, the light doesn't turn off at all.
Apparently, the pump is now completely broken.
Considering the residual value of the A3 (approximately 5000-6000), I really don't want to invest that much more money into it.
Are there also such pumps available used somewhere?
Or perhaps something else is broken?

Can anyone help me with this? It can't go on like this without ABS (and without the driving skills of someone like Walther Röhrl).

Regards,
Frulle.

Have you ever replaced the fuse?
I assume you have read the above posts...

Sure, I've read the articles.
I haven't checked it yet (I plan to do it this weekend).
I'm leaning more towards the assumption that the pump is actually broken.
My writing was more geared towards providing a cost-effective alternative.

Okay, if that part has somehow expanded – which I highly doubt – then check out websites like www.r-a-r.de or www.retek.de. However, I think your described problem is most likely caused by a poor connection. It might be intermittent at first, and then become permanent.

Keep us updated.

Sure, no problem.
The fuses in the A3 are likely located in a box above the battery.
I just took a look at them – they still seem to be in okay condition. But I'll get some new ones. Hopefully, it will make a difference...

Frulle wrote:

The fuses are probably located in a box above the battery in the A3. I just took a look at them - they still look okay.

Also, does that also apply to the battery terminals?

I think so. They are 3 x 30 Ampere (green) fuses, similar to the one mentioned for the Bora (see above).

@ Frulle

The three fuses looked perfect and are working correctly. The problem for me was the base of the fuses. I would recommend cleaning the contact surfaces with fine sandpaper (it's difficult to reach, and you have to be careful not to bend or damage the contacts). If that doesn't help, you'll probably have to replace the entire unit. According to my information, you can't buy the pump separately; it's only available as a complete ZSB (Zündsteuergerät/ignition control unit) with the valve block.

Best regards, Günni.

P.S.: Did you also check the two-pin connector that goes directly to the pump? Mine was fine, but even here, contamination can cause the same type of error. Good luck, and please keep us updated.

Hello, I'm having the same problem. I also started a thread, but I didn't see this one. In my case, the ABS light would occasionally come on, but for the past six months, it's been on constantly, and the error code from the diagnostic system can't be cleared. I've bought a new pump with control unit, but I've heard that you have to overwrite the software code from the old one when replacing it. Is that true? If so, how do you do that? Is it possible to check the pump?
Thank you.
Martin.


I have an A3, model year 1996.

Hello highspeed1.

I don't know off the top of my head how to code the control unit (there's probably a specific section under 'Adaptation,' I think), but if your vehicle's configuration (all-wheel drive, diesel, ESP, EDS, ASR, etc.) isn't the same as what's coded in the new control unit, you're likely to encounter problems. Ideally, if possible, you should read out both codings and compare them (this isn't a problem with VAG-COM). Unfortunately, I don't have a breakdown of the coding string, but a knowledgeable VAG dealer might be able to help you with that.

You can test the pump by disconnecting the two-pin connector and directly connecting plus and minus from the battery to it. But please pay attention to the polarity. I don't know what happens if the pump runs in reverse. However, I would definitely do this test before you start disassembling the entire unit.

Okay, if you happen to have ESP (which is unlikely for a car of your age), it's possible that the pump is internally powered. In that case, unfortunately, it cannot be tested.

Good luck, and best regards, Günni.