T6 rear wheel ABS sensors

[Stephen Harris]

Hi Everyone.
I have looked through similar posts but can't find my specific problem.
I have a 2018 T6 transporter and recently had a fault on the abs . I used an "icarsoft Professional" scanner to find that it was the rear left wheel sensor.
Message read "short circuit or fault to ground or wrong part fitted".
So I replaced this and the right hand one ( acting on advice from a pal). New sensors were genuine VW with the same part numbers on them as the old ones.
Upon rescan I've lost the original fault but now have C101C4A "ABS rear speed sensor incorrect component installed" and still have the faults on the dash showing,
They will not clear if I try to erase them. And ,as my friend suggested, they don't go off if I drive it after the erase.
Advice please as I don't have much experience with the scanner yet!!!

 

[mmi]

Message read "short circuit or fault to ground or wrong part fitted".

Upon rescan I've lost the original fault

What was the code of the original fault.

now have C101C4A

This is fault of the rear left sensor. Is the right sensor ok?

New sensors were genuine VW with the same part numbers on them as the old ones.

Were the parts from VW dealer?

 

[Stephen Harris]

Hi and thanks for the quick replies.
Sadly I have mislaid the note I wrote with the original codes.
Both new sensors are showing the C101C4A code and same fault.
Now my alarm bells are ringing as they came off E-bay and advertised as genuine, from Germany.
Exactly the same part numbers as the originals, plus a VW emblem molded into the plastic.
I contacted the seller before I bought them via an e-bay message and he confirmed that they would fit.
I have just sent him a message asking if they are defiantly VW.
Will come back on this when I now and also, tomorrow, I could put the right hand sensor, whish didn't show a fault originally, back in and test again.
I will be glad when I get my original Austin mini back on the road. I didn't have much trouble with that !!
Thanks again.

 

[mmi]

Both new sensors are showing the C101C4A code

I guess not??? I would expect the rear right to show code C101D4A
Sensors left/right got mixed?

I could put the right hand sensor, whish didn't show a fault originally, back in and test again.

Sounds like a plan

 

[Stephen Harris]

Apologies, my bay writing, the right is indeed C101 D 4A.
They are handed but I suppose the can go in the wrong way if plugs will go in.
I'll check tomorrow (afternoon) and comeback on this.
Thanks.

 

[Lubrown]

I had a rear ABS sensor replaced and got faults again. Turns out the new sensor was also dodgy! Another new replacement was fitted and has worked perfectly since.

Could be the case for you too although I feel the chances of two new sensors both being duds would be incredibly rare.

As mmi said - check the handing and if it’s not that then, as you suggest, refit the working sensor as a test. You’ll then know something more at least.

 

[Stephen Harris]

Thanks. I have heard back from the e-bay supplier and he assures me they are genuine and has not had a problem before, Also he has checked on other sites and they are for my van. I can get a refund or replacement from him.
Will do the tests and handing tomorrow if it's not pouring with rain and let you know.
Thanks again.

 

[MikeWillmott]

Got mine from GSF not expensive and not OEM (can’t remember the brand) but no errors!
Did one and the other failed a couple of weeks later!

 

[Stephen Harris]

Hi All.
Sorted----Sort of ????
Got it to bits again and first I found lots of greasy gunge under both bearing dust caps, which I cleaned out. Don't understand this, the van now converted to camper van has only done 22500 miles from new !!
Replaced the right hand sensor with the original one, (which didn't show a fault in the first place) and cleared the fault on that side.
So it must be that these sensors are no good. What a waste of time.
Have messaged the e-bay seller and he should refund me.
I will try GSF, there is a shop in Kidderminster and we pass them regularly.
Thanks for all the help so far, will keep you informed.

 

[Salty Spuds]

Hi All.
Sorted----Sort of ????
Got it to bits again and first I found lots of greasy gunge under both bearing dust caps, which I cleaned out. Don't understand this, the van now converted to camper van has only done 22500 miles from new !!
Replaced the right hand sensor with the original one, (which didn't show a fault in the first place) and cleared the fault on that side.
So it must be that these sensors are no good. What a waste of time.
Have messaged the e-bay seller and he should refund me.
I will try GSF, there is a shop in Kidderminster and we pass them regularly.
Thanks for all the help so far, will keep you informed.

I recently changed my rear sensors, I used Bosch ones from my local motor factors. IIRC they were around £25quid each, not the cheapest but they fitted and worked faultlessly first time.

 

[Stephen Harris]

Hi again.
Got my refund off the e-bay seller.
Looked at GSF and their price was £14 ish for the Left and £19 ish for the Right. How bizarre !!!
They were Bilstein make, so put the part numbers into Google and came up with a firm called "Opie Oils Limited"
Ordered the pair for £19.44 including postage.
Should be here in a day or two.
Again, will let you know how it goes.

 

[Stephen Harris]

At last I got the Bilstein sensors from "Opie Oils Ltd, (they were a bit slow in dispatching them) and they have cured my problem. YIPPEE !!!
Part numbers are 23822 and 23824. Just Google the number and you will get the best deal.
Once again, many thanks to all who helped me through this.

 

[SlothBurger]

I'm getting a similar fault on my left rear that appeared today. Got a flat repaired teo weeks ago & all seemed ok since then until today. Not sure if related to the flat tyre.

Are new sensors difficult to fit?

 

[mlh677]

@SlothBurger - you will find some tips that are likely to make for an easier sensor replacement in the following thread:-

Post in thread 'Faulty wheel speed sensor [Replaced]'

9 Mar 2025

Thanks to @Loz and other contributors for this hugely useful thread!

I got caught out by a failed NSF sensor just before my MoT in January and timings meant that I paid for the garage to fix it.

This thread has been invaluable in recent days (along with other nuggets across the site) as my OSF sensor started to report intermittent faults a few weeks ago and gave out completely last week, bringing with it the associated ABS/ESP/Cruise Control & Stop-Start errors.

Hydraulic Jack & Axle Stands in place I set about the removal, with penetrating oil, grease, woodscrews & claw hammer...

• mlh677

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