I had some strange behaviour with my abs dash lights today.  Firstly all three dash lights (abs, esp and tpms) were intermittently coming on and off, before staying on for the latter half of my journey to work.  I initially thought it may be the Tevez issue but when I stopped the car and work and restarted only the abs light stayed on, so suspected something else was at play.  Even more strangely when I got back to the car after work and started it, the abs stayed on for a bit longer than the other two which cleared as expected, and then itself cleared after 50m, and never returned.

 

I hooked the car onto VCDS when I got home and it had recorded an intermittent fault with a rear abs sensor, so I am assuming this caused the strange lighting behaviour. What is slightly worrying me is that the lighting behaviour wasn't consistent, all three on or off all the time and I'd understand, but not what occurred.

 

I cleared the fault and plan to wait till it reoccurs (if it does) but should I be worried about the varying dash lighting behaviour?  And am I looking at a lot to replace a sensor if required?

 

Thanks

Adam

ABS Wheel Speed Sensor (Rear Left) is a fairly common fault on the MK II Octavia, lighting-up the dash as you describe.  Usually it's caused by the rear wheel bearing, rather than the speed sensor itself.

 

There's a magnetic ring attached to the wheel bearing, the ring gets corroded and then it starts to flake away or make contact with the speed sensor.  The rear wheel bearing will probably need replaced, but sometimes the ABS sensor gets damaged too, where the rusty ring scrapes against it.

For me, it was just case of replacing the rear hub (picture of old / new hub here).

 

If your a competent DIY-er, there's a link to a write-up on this thread, but it does need some special tools, the spline bolt holding the hub in place is incredibly tight and needs to be torqued back up the same.

 

While I wouldn't guarantee this is the problem, I'd reckon it's fairly likely (and tends to start off intermittent).

Meant to say, you can price up the wheel sensor and wheel bearing on Euro Car Parts.

There's usually some promo codes floating about that'll get you around 30% off the list price.

Thanks Ross, very useful replies.  Was the wheel bearing integral to the hub you replaced?

Meant to say, you can price up the wheel sensor and wheel bearing on Euro Car Parts.

There's usually some promo codes floating about that'll get you around 30% off the list price.

I have just had the xmas tree lights and have read the codes and looks like a left rear wheel sensor.  Would you recommend just replacing the sensor first or stripping it down and checking the condition of the ring for rust and flaking.

 

Also, silly question, but when it says left rear, are we talking drivers side rear.  As you look at the front of the car its the left side ???

You how too guide will hopefully be very valuable to my quest and i thank you in advance.

 

regards

neil

The common fault seems to be the ring, which gets badly corroded and the magnetic ring deteriorates.  The corrosion can sometimes start impacting the ABS sensor as the wheel rotates, making it go faulty too (but most cases I've heard of, its just the ring that needs replaced, not the sensor).

 

Rear-left is as-if your sitting in the car.  So in the UK, it's rear passenger side.

 

It wasn't me that wrote-up the guide, but its the one I followed and worked a treat.  Only thing, don't underestimate how tight that bolt is holding the bearing in place.  I had an M18 spline attached to a long breaker bar, it wouldn't budge.  Ended up buying a metal gate post for extra leverage..then later returning it (thanks Wickes).  Obviously, it'll need re-torqued to the same level.  The caliper bolts (M14 spline) are a pain as well.

 

Oh, and yes - the sensor ring, bearing and hub are all the same part.

Yes mine was a rusty ring too..

nothing worse than a rusty ring. I've had the RL sensor fault too.

apparently there are 2 size of hub 30mm  &  32 mm dont no what to buy any ideas 2008 octy estate 1.9 tdi help  

Look at the link below, 

 

https://skoda.7zap.com/en/cz/octavia/oct/2008-419/5/505-505005/

 

You should be able to cross reference with ECP,

 

I believe the answer is 32mm looking at the pictures.