Greetings all..

 

My mother's Fabia 2 1.4 TDI (drums on the rear) has a fault with the n/s/r ABS/speed sensor ring. We've changed the sensor plug, still throws up the ABS warning light. DTC codes 00290 and P1857. Think it must be the magnetic sensor ring (or is 'reluctor ring'??). Assuming this is fitted in the hub? Is it a seperately changeable item or does it need a new hub?

Edited 27 June, 20214 yr by Strugs

Yes the rear hub needs to be changed, watch which hubs you buy as some are advertised as fitting the rear on the Fabia but are not ABS hubs, some are ok but are poor quality bearings and fail after a few months, I bought replacement rear hubs with new caps  and nuts from Germany on ebay  they were around £95 for the pair but lasted 3 years but we sold the car so don't know if they are still going strong, easy job to do but remember to pull sensor out a bit from the backplate before removing the hub and putting new one on as you WILL damage the sensor if left in place

21 hours ago, Murdockman said:

Yes the rear hub needs to be changed, watch which hubs you buy as some are advertised as fitting the rear on the Fabia but are not ABS hubs, some are ok but are poor quality bearings and fail after a few months, I bought replacement rear hubs with new caps  and nuts from Germany on ebay  they were around £95 for the pair but lasted 3 years but we sold the car so don't know if they are still going strong, easy job to do but remember to pull sensor out a bit from the backplate before removing the hub and putting new one on as you WILL damage the sensor if left in place

 

Cracking, cheers 

Hub changed. ABS light still on! Time to chase the wiring break now.. 

Have you read the fault codes ? could be and most probably is latched and needs clearing from the ECU...................this is assuming you have not fitted a who flung dung hub assy.

18 hours ago, UrbanPanzer said:

Have you read the fault codes ? could be and most probably is latched and needs clearing from the ECU...................this is assuming you have not fitted a who flung dung hub assy.

 

Haven't read the code since fitting the hub, but I thought the ABS reset/checked each time (I.e. would self-clear when problem is solved..)?

not normally, they are often a latched fault.

Strugs, have you done any other modifications to the car? I had an ABS fault on my rear left which came on and went, over and over. Swapped out the sensor twice, still did it. Took it to a specialist, told them I heve swapped the sensor twice already, they did it again, charging me over £200 just to do exactly the same thing, light up after a short drive... They then did a swap of left to right bearing/reluctor ring, fault persisted, did a continuity test, no difference. Then though winter, it sort of cleared up mostly. Back to warmer werther, it started to come on agin. I recently reverted back to standard, a few mods I had fitted. (Auto lights, certain LED bulbs from rear lights, sidelights, etc). Since doing the reversion, I have not had an issue with the ABS light coming on. I have had lights on and off, done countless emergency stops, basically tried to make the ABS come on but it has since stayed away. I am thinking it may just have been some sort of voltage glitch... Oh, it seemed to happen less when it was happening, if I made sure the battery was fully charged so that again, suggests a glitch somewhere in the voltage. Might just be me/my car but think about any things you may have changed/added.

All this started around the time I had a student who did mini-emergency stops, every time he braked, until he got used to driving again after a ten year absence. This did coincide with the same sort of time I fitted the auto lights switch and LED bulbs, hence my reasoning!

So, the fault code kept saying 'Electrical fault' in relation to the ABS/Speed sensor on that wheel. Have checked the continuity of the wire and all good. So, the conclusion now is it's a failure of the ABS pump/ECU which is a right pain in the 'arris!! Apparently relatively common on certain VAG products and the only fix is replace or refurb. Bugger! 

what hub did you fit ? can you prove the hub is good

 

seems odd that the fault has changed........

 

What is the code ?

Edited 13 July, 20214 yr by UrbanPanzer

The code was 00290 "Left Rear ABS Wheel Speed Sensor" with the state: 'Electrical Fault in Circuit' and that's not changed. The hub was one from Autodoc. Interestingly, having unplugged the loom at the ECU end to check the continuity to the sensor, which - as I said, is fine - and the plugging the loom back into the pump and setting off, it took a good while for the ABS light to come back on (gave me false hope that unplugging and plugging in had cured it! ) which, to me, indicates it's the ECU/ABS pump..  

That code relates to the circuit / wiring to and or the sensor.

 

If the wiring rings out ok, then it is most likely the sensor that is faulty (assuming new hub is good)

 

Why did we go for hub ?  Has a new sensor been fitted ?

 

If the wiring rings out ok, then it is most likely the sensor that is faulty (assuming new hub is good)

 

A basic "test" you can do of ABS sensors is to measure it's resistance, this way the one that is way different to the others is the faulty one. So "if" you have not fitted a new sensor (yet) then measure the resistance across the sensor

pins at the "faulty" side and compare to the good side.

 

Edited 14 July, 20214 yr by UrbanPanzer

I was told it'd be pump too but now the issue has sorted itself, after re-fitting normal lightswitch and normal bulbs to sidelights, etc. If you can see the pump, try checking for cracks, though as water/moisture may well ingress and cause issues. Dry it with hairdryer and put sealant over any cracks found.

17 hours ago, UrbanPanzer said:

That code relates to the circuit / wiring to and or the sensor.

 

If the wiring rings out ok, then it is most likely the sensor that is faulty (assuming new hub is good)

 

Why did we go for hub ?  Has a new sensor been fitted ?

 

If the wiring rings out ok, then it is most likely the sensor that is faulty (assuming new hub is good)

 

A basic "test" you can do of ABS sensors is to measure it's resistance, this way the one that is way different to the others is the faulty one. So "if" you have not fitted a new sensor (yet) then measure the resistance across the sensor

pins at the "faulty" side and compare to the good side.

 

 

I'd already changed the sensor, and now the hub. Yes, can't necessarily odds that either of those new items isn't faulty, but I'm not sure I'm left with much else now other than the pump? 

14 hours ago, mrgf said:

I was told it'd be pump too but now the issue has sorted itself, after re-fitting normal lightswitch and normal bulbs to sidelights, etc. If you can see the pump, try checking for cracks, though as water/moisture may well ingress and cause issues. Dry it with hairdryer and put sealant over any cracks found.

 

Just bought a warrantied pump on ebay for 50 quid.. Now where's the fingers-crossed emoji!?  

Hello - I have this fault and am in the place where the pump is what is left to do. Did replacing it work?

Many thanks

Since @Strugs isn't following this thread, and hasn't been on the forum since February, I've tagged him to hopefully cause him to get an email notification about your question @Hindsite.