2008 VW T5 Transporter T30 4motion 2.5TDi BNZ

Had a really strange issue on this.... no lights, no faults prior to doing this work.
The Van went in for it's annual MOT and it failed on various suspension items. So adopting the whilst in there, we replaced everything on the front to make it "as new".
We replaced on both sides at the front
wheel bearings
drive shafts
ABS sensors
Shock absorbers
Springs
Top mounts
ARB bushes
Tie rod ends
bottom ball joints etc etc

built it all back up and we had a 00285 mechanical fault in ABS sensor G45 (front right)... after replacing the wheel bearings 3 times (found 2 were faulty and not giving a reading) , and 2 new ABS sensors, all the wiring was checked back to the ABS ecu, both voltage and continuity and all checked out perfectly. Even physically checked the actual wiring to see that there wasn't any bad joints etc.

On VCDS you can see in measuring blocks 001 all 4 ABS/Speed sensors and you could see the readings, so communications were there, as soon as you drove above 25mph (40km/h) the ABS light came on and the fault reappeared. When driving and looking at the measuring blocks you could see the speed drop on the G45 sensor where the others kept a stable reading.

The Van has gone to a garage (who's owner is usually full of BS) and we asked him to realign the front suspension as it was out after the suspension rebuild and he says he has recalibrated the sensor and we now don't have any warning light or fault code..... I could not find anything on VCDS that allowed us to recalibrate anything, what has he done?

Also before it went to him the speed sensor would read actual speed, now it stops reading at 49-50km/h on all 4 ABS sensors...?

Any ideas at all as i'm baffled......???

Genuine VW sensors used?

Delphi Sensors and FAG bearings... nothing cheap or chinese

The light is now off, the only thing done is the wheel alignment and the garage saying they've recalibrated the sensor??? nothing has been changed since it went back down onto the wheels

I'm not aware of anything that can be "calibrated" with an ABS wheel speed sensor either.

Is it possible he tweaked something mechanically?

-Uwe-

The light is now off, the only thing done is the wheel alignment and the garage saying they've recalibrated the sensor??? nothing has been changed since it went back down onto the wheels

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Height change from fresh suspension will do this and require all to be relearned, especially SAS!

Please Post an auto-scan.........

Often after UN FOD of a lowered vehicle back to factory ride height I run into this!

What do blocks say in the count for wheel speed?

I agree with Jack - SAS calibration did the trick.
BTW MVB information are showed with some delay, not a perfect source of accurate measurements for relatively quickly changing parameters. The VC-Scope can show a bit better info, at least graphical representation can show You unusual drops or rises of signal, that You can miss looking at four boxes with figures changing.
Strange, that You got VSS signal readings for speed up to 50km/h. Normally almost all known ABS/ESP modules drops the diagnostic connection when speed exceeds 20km/h for safety reason.

There was no issue with the Steering Angle Sensor though.

There was no issue with the Steering Angle Sensor though.

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Correct but the height on the tie rods changes over all length for push back of suspension when higher and can tweak the SAS and is why I recommend you should re-calibrate.

All I can tell you is it has worked each time for me & I hope it does for you!

Sucks you have to get stuck changing a bunch of parts to find this out!

One of the new bearings was dead from the get go.... It wouldn't communicate with the sensor (this was why i ended up checking all the wiring).
Replaced the bearing and sorted that...

I agree it must be the SAS, i just wished I'd found it rather than the guy at the garage. Every day is a school day and the issue is now logged in my memory...