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Discussion Starter · #41 ·
Interested to see how this gets resolved. I had an intermittent ABS error on the dash at the weekend. Stopped the van, switched off and restarted a minute or two later - still there. Carried on for a bit then stopped again at some roadworks, switched off whilst I was waiting and pumped the brake pedal a couple of times just to check the pedal feel. When I switched back on, ABS light gone.
I need to do a full scan but I'm assuming it's going to be a sensor issue.
That sounds exactly the same as I had. Started off intermittant. Now on all the time. Investigations to continue today.
 

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Discussion Starter · #42 ·
Update for today.
While the crimps were all exposed, I took the opportunity to do some testing with the sensor working live. Chocks on wheels, gearbox in park, handbrake off. Jack up and remove rear wheel. 11.2V across the wires whether sensor connected or not. Resistance between wires around 800 ohms and didn't seem to change a lot when I turned the wheel. Found a video where they measured the AC voltage across the sensor and this would change when the wheel was turned. Did this and got a very small change (0.2V maximum) which is much less than shown in the video.
Running diagnostics showed open circuit when sensor was disconnected and no error when connected. However, I'm not getting any speed detection on this wheel when I turn the wheels.
Had a look at the ABS sensor ring on the rear wheel. I've seen videos that show covers on both sides of the hub, but there aren't any on this van. Sensor ring was covered in muck so gave this a good wipe. Didn't really expect it to make a difference but you have to try! It's all completely open to the elements there so I wouldn't be surprised if dirt can start to wear away the sensor.
I'm fairly certain it's not a problem with the wiring so it's coming down to the sensor, ring or ECU (don't want to think about that one as it's probably going to be expensive). I think I should be able to do the sensor so going to order one of these. eBay ones seem to be around the £9 mark. Car parts stores up to about £43. Do the eBay ones work?
 

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At least it's not a huge outlay if the £9 one doesn't pan out. I scanned mine last night and it's showing as an intermittent fault with the rear right sensor. Cleared the codes and took it for a drive. Nothings returned (yet!) so I'll wait until something does. Hopefully it was just some crud in/on the sensor. Following your thread though in case mine follows suit.
 

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Discussion Starter · #46 ·
Oooo! ABS sensor turned up today as we were out watching James Bond. Trolley jack and axle stands to be picked up tomorrow morning so hoping to get this in later on. Fingers crossed!
 

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Discussion Starter · #48 ·
Took the van down to Halfords and half way there the ABS and ASR lights went off. Still off for the return journey so not sure if I should replace the sensor now. Thoughts - did cleaning up the sensor ring solve the problem? Has the muck been blown out by a quick blat down the A12? Has the ABS module now "tuned in" to the different signals coming from the sensor? Tempted to take it out for another drive and see if it stays fixed (I do enjoy driving it!)
 

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Discussion Starter · #49 ·
Lights came back on right at the beginning of the test drive :(.
Back home, Jack up with nice new trolley jack. No idea where you're supposed to put the axle stands. It's all plastic underneath so wheel off and stuck it under the suspension bits.
ABS sensor connector off, unscrew using 5mm Allen key, then wiggle it until it comes out. Fitting new sensor just the reverse.
Fired up OBDeleven and set to monitor wheel speed. Quick turn of the hub and bingo, we have a speed!
Put it all back together. Only tricky part was refitting the plastic guard around the wheel arch. Couldn't remember where all the screws went. Worked it out in the end.
No errors on the test drive so I think I've fixed it (shhhh!).
Quick note for anyone else replacing sensors. There are left and right hand versions. Front and rear are the same so don't worry about all the cheap ones saying front only.
 

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It's a common fault and apparently can also be wiring related, I have these bookmarked for when I next try to sort mine, although I think mine is the passenger connectors, as if I leave the seat alone it says off.



 

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Just popped out,sounds a dream 😂 I did mine on my RS4 and ended up with it snapped in place and had to remove drive shaft and knock it through 🤦‍♂️👍
 

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Discussion Starter · #53 ·
@JonR the first thread you link to is really useful.
As I said above, I pulled the loom out to check for dodgy crimps but all was OK. My van is a LWB so don't know how different this is to a SWB. After pushing the wiring loom out from the wheel arch, I couldn't find it by poking a hook through the rear light access points. Found it was much easier going in behind the wheel arch from inside. I've still got the original shuttle plastic trim so there's easy access into the void where the cables live.
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Another thing, when putting it all back together, undo the screws holding the rear underside plastic cover to get better access when putting the grommet back in place.
 

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Discussion Starter · #54 ·
Just popped out,sounds a dream 😂 I did mine on my RS4 and ended up with it snapped in place and had to remove drive shaft and knock it through 🤦‍♂️👍
You have to wiggle it quite gently, especially at the start. I didn't think it was going to move, but after a minute of gentle persuasion it started to move. 15 seconds later it was out. On a T5.1 you have fairly good access to the sensor so shouldn't have to remove the hub or anything that drastic. Seen a trick where you heat a screw and push this into the sensor plastic and just pull it out. Can't find the video now, but have a search on youtube.
 
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