ABS continuously regulates after sensor replacement while braking at speeds below 20km

Hello,

After I had to replace the wheel bearings for the first time, I also replaced the ABS sensors at the same time.
When pressing the bearing in, the bearing seat was verschandeln up to the mounting point, and I also pressed the ring in completely, but I had to "redo" both sides, as it didn't want to slide in easily during the pressing process.

Unfortunately, the ABS system only activates at speeds of approximately 20 km/h and until almost the end.
The car brakes perfectly without any issues, and there's no need to press the brake pedal (I also completely replaced the braking system).
So, I removed the sensors and properly cleaned the hole again.
And nothing happens. The same problem as before.
Reading the measurement data during constant speed results in constant outliers for both sensors, mostly higher values. Otherwise, they were based on the value of the rear.

/viewtopic.php?p=175271#175271

The rear sensors always provide identical values, without any outliers.
Now I have already tried searching the forum, and I have also found the same question, but I haven't found a solution yet.
As I suspect, the ABS ring is located in the bearing, which I have now completely pressed in.
Therefore, the error should actually be ruled out.
Or perhaps not?

Please set the sensor values to default. ABS sensor malfunction?

Hi "Fabia"!

Know the error from my A4 and here is a broken ABS sensor ring!

Capture the vehicle, remove the wheel, remove the ABS sensor, and then (if necessary, using a hand mirror and a good flashlight) carefully inspect the pinion gear through the opening. Of course, "the wheel" should be turned slowly.
I'm sure you'll find something here. Whether it's metal shavings, a crack in the sensor wheel, or something else.

Best regards from Munich!

PS: Of course, the same procedure should be followed on the other (bicycle) side

Hello DieselBär,

Thanks for your tip,

Unfortunately, it doesn't work as simply as you think, especially with models like the Fabia, because there isn't an external ABS ring on my wheel hubs.
The wheel bearing is pressed into the hub and is then pressed into the housing as a complete unit.
The sensor is located vertically, from above, within the wheel bearing housing and is positioned sideways next to the wheel bearing.
6Q0407621AJ
Or, in simpler terms, the "gate unit" should be located in the valve/seal unit.

So, I can't imagine that the unit in the wheel bearing should be defective.
But sometimes, that's just how it is.
Unfortunately, this was also my initial concern, that errors with the ABS could occur after the change.
Whereas faulty sensors would be the least of the problems. I'm just wondering how one can check the function of the sensor wheel in the wheel hub, both before and immediately after installation?

Then I guess I should try the simplest version first and try it with new sensors.

Best regards from Braunschweig to Munich

Hi Fabia!

Take a look and see if you like it better:
/viewtopic.php?t=1150&highlight=abs+fehler+radlager
Was ist das Ergebnis meiner Suche *Anmerk*

Best regards from Munich!

Well,

I have now completed cleaning the ABS sensors, and immediately after starting the car, the warning lights are immediately illuminated.
After some time, the red warning light will also illuminate. The game repeats itself after every engine restart and needs to be re-started.

Unfortunately, I just learned that a special magnetic card can be used to check the integrated ABS rings.
/viewtopic.php?t=24086
Then I would at least have been on the safe side that the wheel bearings were failing.
"I have already found your link. However, as shown in the image with the wheel bearing unit, a significant number of errors can be introduced during assembly using this type of wheel bearing with an integrated ABS ring. Unfortunately, it is not possible to check the magnetic ABS ring while it is installed. Reliable information can only be obtained if the bearing is defective." Can rule out ABS sensors.

Ahhh, NOW I understand what you mean

No, at this point, I also can't think of anything else personally *sorry*

For this, I will at least make your image visible:
[img]/download.php?id=4870[/img]

Best regards from Munich!

The wheel bearings must be very old if AJ has even been able to fit them
These were changed by the manufacturer in 2008 to AD, in 2009 to BR, and in 2010 to 6R0.

I really hope I didn't get outdated wheel bearings.
Since I didn't have my own photo yet, it should only be for searching.
But in the photo with the magnetic card, everything is now visible.

Unfortunately, these cards are not available everywhere. Some manufacturers sell these bearings for around €5.
But it's cheaper than a wheel bearing because of the defect. Replacing the magnetic ring.