Good evening everyone, earlier today I had the abs/TC/TPM lights all illuminated on my car's dash, so when I got home I plugged my obd in and I got the code 00290 left rear abs wheel speed sensor so I've ordered a new one (Bosch for £17). Just been reading that people have had to replace the hub in some cases, is this a common issue or more likely to just be the sensor does anybody know please? My cars a MK2 Octavia vrs tdi. Thank you guys 👍👍

I had problems removing old sensor on mine as it was rusted in. Snapped it when removing but as I was replacing bearing anyway managed to get old bit out. Give it a good soak with penetrating oil for a day or two if its stuck and hopefully it will come out. If it snaps you may have to remove hub/bearing etc to remove broken bit. Check the condition of the connector and wiring as well first as if theres a fault it will put ABS light on.

Alasdair

One way to remove the sheared off section, seems to be to heat up a suitable sized chip board screw "as it has big deep threads" and force that down into the remains of that sensor, then add in 1/2 a turn or so of rotation. Cool that area back down using maybe ice-water, to improve the chances of shocking the plastic away from the metal hub carrier, then when cold, grab the screw and pull it up and so out.

I've bought Bosch replacement ABS sensors for my cars in the past, the first one was needed when I "bent" the end of a front one on a 2015 Polo when pulling out the bearing assembly, one side I got off with, the other side not so lucky! Next time was my 2011 Audi S4, in that one, I ended up with an ABS fault - front RHS wheel sensor, now, on that one I used an old "brake wear indicator lead" as a test lead, and that ABS sensor's resistance had dropped to 1.4KOhms - for that car they tend to be roughly 500KOhms, and few days later I measured it again, it was 0.7Ohms! So, in that case I've worked out(after checking the surface of the newly fitted ABS sensor), that, as said on advice given to me on another forum, the inner surface of the bearing is probably corroded and is pushing the magnetic strip out and it is now in contact with the "finger" of the ABS sensor, so this replacing this sensor won me an MOT, but is not the final fix - that is yet to happen when the weather gets warmer!

I've made up a tool to help remove these sensors, I've made up a 6mm version and a 5mm version - just in case one size suits this situation better than the other.

Other ways to remove them seems to be just drilling a suitable sized hole, taking care not to drill down too deep - your new ABS sensor will guide you on that, then screw in a suitable sized chip board screw, then yank it out.

Apply some non conducting grease to the upper end of the new ABS sensor so that it will be easier to remove in the future - if you have to, also, if it will be smart to remove after maybe 100 miles to see if there are any scores on the end of it which would indicate that you have not approached the root cause of this failure - ie it is a wheel bearing issue!

Edited 31 March, 20251 yr by rum4mo

Hi guys, thank you for your advice I will bear this all in mind if I pluck up the courage to do it when the sensor arrives, I don't understand tho why it throws the TPM light on tho? Guess it's just all linked?

Always wondered as my Seat has the same system but not the system that has individual sensors in the valves. Turns out it is related to ABS sensors. How it works is beyond me. Perhaps a low pressure tyre reacts differently? As said give the offending sensor a good soak with plus gas or similar if its stuck. I have been using a mix of 50/50 ATF and petrol recently with good results. Hope your car isn't as bad with corosion as mine. Too much salt on the roads for my liking in my part of the world. Wish they would bring back tyres with the steel studs in them and stop using salt. Its death to cars and below -5C doesnt work well anyway.(sorry about the rant) Good luck

Alasdair

7 minutes ago, Alasdair1 said:

Always wondered as my Seat has the same system but not the system that has individual sensors in the valves. Turns out it is related to ABS sensors. How it works is beyond me. Perhaps a low pressure tyre reacts differently? As said give the offending sensor a good soak with plus gas or similar if its stuck. I have been using a mix of 50/50 ATF and petrol recently with good results. Hope your car isn't as bad with corosion as mine. Too much salt on the roads for my liking in my part of the world. Wish they would bring back tyres with the steel studs in them and stop using salt. Its death to cars and below -5C doesnt work well anyway.(sorry about the rant) Good luck

Alasdair

Indirect TPMS uses signals from the ABS wheel sensors to compare the relative rotation of each wheel - if a tyre loses pressure, its circumference reduces, resulting in a change to its rotational speed in relation to the other wheels.

The system can also be triggered by increases in pressure caused by an rise in temperature in one (or more) tyre.

Presumably, the system averages-out the normal differences in wheel rotational speeds resulting from cornering.

Yeah I did increase the pressures in them 10 days ago as we was going away (3 people and a German shepherd in the boot so I presume now with the weather warming up that could have bought the light on to say there now to high, il check them tomorrow see where there at👍 and yeah the salt is a ****ing mare mate I always hose pipe the underneath of my car when I'm cleaning it just to help get the salt off!

If the tyre pressures are equally high - and remain within the detection tolerances of the TPMS from when they were last set, raised pressures will not trigger the alarm on a indirect system.

Indirect TPMS detects changes relative to the other tyres.

Edited 1 April, 20251 yr by Warrior193

Hi mate, I did check them earlier 3 were on 32psi and the left rear ( the one with the abs fault was 33) so all ok really I dropped it to 32 so all the same now, mechanic I use can't do it till next Wednesday but I don't do high mileage so il be ok 👍

Ran my car with ABS light on for weeks until I got round to fixing it. Brakes still work but no ABS. If theres only 1psi difference I assume its the sensor thats causing the problem.

Alasdair

Yeah I assume so mate as it's only come on since the abs light, I'm impatient so next Wednesday can't come soon enough spec when it comes to my car 👍😀

I had an intermittent ABS error for months. Finally fixed it in anticipation an MOT, it was the pump on its way out.

Afternoon guys, just an update. Had my abs sensor done earlier and all good mechanic said it came off ok bit of a struggle but all 👍. No more warning lights on the dash 🙏👍. Thank you all for your advice much appreciated as always guys 👍