Problem with ABS wheel speed sensor on Audi A6 C4

Hi!

I have an A6 C4 where the following error occurs: 'Speed sensor, front right, signal interrupted.' The error can be cleared, but it reappears as soon as the car is driven for more than 20 meters. Okay, so if I unplug the ABS sensor, the error code appears immediately when I turn on the ignition – that's understandable. But in my case, the error code only appears after I've driven a few meters (10-30 meters).
Okay, here's the translation:

'I have a new ABS speed sensor here. I measured its resistance with a multimeter and got 1.3 kOhms. The two sensors in the vehicle both show an Ohmic resistance of 1.23 kOhms, so the new sensor should be fine. Is a speed sensor basically just an inductive Hall sensor?'

Well, I'm at my wit's end now, and I don't know what else to do... I almost think changing the sensor is nonsense, since it costs 160 euros and unfortunately gets destroyed during removal... almost always .

Please help!
Best regards,
Martin

In my opinion, everything is clear.

Ohms' law doesn't necessarily mean that the component also exhibits inductive behavior.

Because the "R" is present, it's initially recognized as okay. Then, you start moving, and three sensors report rotating wheels, while one doesn't. So, the engine control unit (ECU) says it's broken.

If the aperture disc is dirty or too far away, the behavior you described may also occur.

A colleague's Ibiza is currently having its sensor replaced - it worked for a while, then stopped working again.

In my case, the two iron cores that face the cutting disc were completely rusted.

Our costs are only 38 EUR.

By the way, all of them, front right!


m;

Okay, but if I try to expand it now (it might be the first one), it will break because it's so tightly stuck. If I replace it and then still have the same problem, it's like throwing away 160 eggs – how can I test this? I can't see the 'radnarbe/lochschiebe/or whatever that part is called,' so I can't tell if it's dirty or not.
I am not a mechanic... just to make that clear .

Best regards,
Martin

'Or can someone tell me how to remove the sensor without damaging it?'

Hi,
Approximately a year ago, the speed sensor on the front right of my A6 (manufactured in 1996) started malfunctioning (the ABS system would engage during normal braking at speeds below approximately 10 km/h). I was able to remove and verschandeln it without any problems, and after that, the issue disappeared. On my car, the sensors have a flange that allows you to relatively easily pry them out of the hole in the wheel bearing housing.

Regards,

Olli.

Hi!
I'm familiar with trying to remove the 'bund' (likely a threaded fastener), as I've tried it on two A6 cars with scrap parts. I tried prying, wiggling, tightening, using rust remover, letting it soak, but every time I used pliers, nothing happened. It wouldn't budge. Eventually, the plastic part separated from the metal casing -> then the contacts inside were torn off .
I'm somehow hesitant to replace the sensor (buy a new one)...
Best regards,
Martin
How can I measure the signal? Where is the best place to connect the oscilloscope?

If you're talking about 96 and 94 ABS sensors here, could it be that they're the same as the Golf 3 sensors, or what?

Because my 12/95 model has the same sensor as my colleague's 2001 Ibiza.

And it only cost 38 euros.

The old insert in my golf club also consisted of a metal sleeve and a plastic inner part...

I wouldn't mess around with an oscilloscope for 38 euros.

Connect the oscilloscope to the two pins of the sensor, which is connected to the ECU (Engine Control Unit).

What is the part number for the Audi sensor?

m;

According to the Audi workshop, the price for one item is 160 euros, including VAT.
4A0 927 803

Okay, I understand that I need to connect the oscilloscope to those two wires while it's connected to the engine control unit (ECU), but the connectors are all so tightly packed that I can't access the signal. I definitely can't do it in the engine bay because of the spark plugs, right?
Best regards,
Martin

TDI... Spark plugs...

AAAAAAAAAAAAAHHHHHHHHHH

Was that a joke of yours?


Yes, I've already seen the prices. It seems like the wiring harness is the issue (but in my case, it's actually just the sensor).

For your oscilloscope experiment, you'll need to build an adapter plug.

Sorry... it's my girlfriend's Audi A6, 2.0, 4-cylinder, 115 horsepower, gasoline engine, model code ABK.
My TDi, of course, doesn't have a spark .
Best regards,
Martin

I disassembled the DZF (presumably a component), and surprisingly, it came out in one piece. I then cleaned and blew it out, reinstalled it, and it's working perfectly again. Apparently, the culprit was dust or fine metal shavings.
Best regards,
Martin

Hello,

In Audi models B3, B4 (possibly also C4 - I'm not entirely sure), the crankshaft position sensors are only plugged in, not screwed in. This allows you to slightly adjust your position during brake replacement or when dealing with vibrations, increasing the distance between you and the impulse disc.
The consequence is intermittent failures in the pulse detection (because the magnetic field's intensity also depends on the rotational speed). In particular, at low speeds, individual missed detections (e.g., one tooth not being recognized) can lead to an incorrectly low reading of wheel speed, which in turn can trigger the ABS system prematurely.
Typically, this happens when slowing down gradually when approaching intersections.
It's best to check if the disc brakes are properly installed, and also be careful not to push them out when changing the brake pads.

Regards,

heating fossil.