jpadie

Thank you. I'm not sure where the abs ECU and pump are mounted in a Fabia but will see how far I can scoot under the car tomorrow morning. The wiring looks ok and is providing solid enough input to the ECU so that Delphi reports continuously The ECU is reporting solidly to OBD. Best I can come up with at the moment is an intermittent break in overly brittle wires. Replacement abs units seem to be more than I paid for the car but it could be that I need to visit a breakers yard.

Any solid way to diagnose it?

Reset the fault codes and took the car out for a short drive. Warning light came back once I hit 50kph. Had a flight recorder going on the wheel speed sensors and they all measured within 1kph of each other the whole time. Brake fluid normal. I've taken the sensor out and scrubbed the area again but I doubt whether that has anything to do with it! Car still drives fine of course. But no abs. And I doubt the driving test invigilator will allow my youngest to take the test with the abs light shining balefully! If anyone has any thoughts for investigation, I'd be grateful.

Well as it happens I've taken it out and the abs error has come back. Not sure whether it's just because it's a stored error or because a new bearing didn't fix the issue. So far new sensor and new bearing and when driving I can see that the wheel speed is being read. So the cable is ok. Not sure what else can be wrong now !

you could be right, Pete! this is a photo of the new one. it looks to me that the bit you blued is the outside of the race-bearing. Although it's static (with reference to the hub) I think it is unlikely that they would manufacture the bearing itself with magnetic zones. but who knows! this other site seems to agree btw. https://www.vweosclub.com/threads/visualize-a-magnetic-abs-sensor-on-a-v-w-wheel-hub.37149/ the proof is in the pudding perhaps - I will take it out for a spin in a couple of hours.

took the bearing off and it looks like the mag-ring was damaged. new one is on and fingers are crossed.

I've ordered a new bearing and will fit it on Wednesday; and give the area a scrubbing in case it's debris (some of the glide plugs are missing, possibly something could have got in and created a deflection to the magnetic field). Unfortunately I'm up against some time pressure as my youngest needs the car to take her test next weekend! Fingers crossed that she can become the designated driver soon.

Thank you. Is there any way to inspect the bearing without dismounting it? I did look at inspecting it when I changed the brakes but found that I could not get the cap off non-destructively.

Hello all I have had a wheel speed error since changing the rear brake shoes a couple of months back. Diag tells me it is rear left. Changed the sensor this morning but the error persists. The cable inspects fine. Is there something I could have done inside the drum to cause the problem? Cheers Justin

Just don't allow it on any network with your other devices and don't allow it to connect to the internet. It's fairly trivial to cross infect over networks, harder but possible to compromise perimeter devices and if it connects to the internet it's entirely trivial to co-opt it into a bot-net or remailer.

Thank you for that @sepulchrave! I've seen on Amazon, eBay and other sites that the purchase of some software scan tools mandates a remote installation by the vendor. This seems profoundly unwise even on a throwaway lappy. I'm still hunting and am on my way to Greece to check out Mount Parnassus.

Oh! is that the trade off? so garages etc have to have different scan tools for each marque?

Dear hive mind I have an OBVEleven dongle (a couple, in fact. although both appear to have been put in _very safe place_). But I'm looking for a general purpose scan tool that can do deep reads, adaptations and commands on most vehicles. I have currently a Peugeot 308 (2014), skoda fabia mk1 (2008 ish), toyota corolla verso (2008), a new style Beetle (2015) and a newish MG (2023).. I'm looking for something that covers these at a reasonable buget (say <200). any recommendations please? Currently I use the obdXI for the skoda and beetle (when I can find it), a special cable and some linux software for the toyota and I have nothing for the Pug or the MG. I'd rather standardise on one thing that I'm less likely to lose!

ah! I did not see this as I never removed the bearing, makes sense though. I've got a 36mm thin wall medium depth 12 point socket somewhere that I've used on other VAG cars. Hopefully that's the right one for the fabia too!

that was the adjuster armature. it. had come off the spring and been thrown out of its housing. how would something inside the drum dislodge the wheel sensor?

yup - will do. took the fuse off and checked again under a magnifying glass. all is well there.

did both sides, cylinders and shoes. I didn't remove the hubs. Just to salve your conscience I will unbolt the fuse and double check. i did give it a good scrubbing with a brass brush and some Isopropyl alcohol.

have lifted the car and the wheel spins well enough. so next stop is to check the wheel speed sensors. unfortunately I can't find my scan tool.

Sorry @Breezy_Pete - I had checked strip-fuse 4 and it's pukka.

Sure. I will lift the car again and see whether the shoes need adjustment. Seems always to need doing on a day I have to get to an airport. If the shoes are grabbing then the wheel may spin slower when driving. I.e. there could be lots of micro skidding on that wheel. I'd expect the hub to be very hot in that circ though. And a quick drive to Screwfix and back just now had both hubs at about the temp of Luke warm bath water. I'm suspicious because the abs light is about the only thing not to have flashed up on the dash of over the last year. Then I change the brakes and it's fine for a week. Then off to the MOT (where it was on the rolling road) and suddenly it's complaining.

Could it (the wheel speed sensor reading) be caused by the rear shoes grabbing a bit at the hub? That was what I was experiencing when I fitted the new shoes. One wheel span perfecly the other needed some effort to turn when the handbrake was off.

Well.... Replaced the brake shoes and adjusted the handbrake and the car was driving fine for a few days. Then I took it for an MOT (handbrake and emissions after a leak in the front of the flex pipe). It passed. As I was leaving the estate on which the test centre was the abs sensor light came on and now is on permanently. I didn't even know that the car had abs. It still brakes fine. There are no electrical connections to the back brakes or front that I have seen. Any thoughts that might help on this? Cheers Justin

I ended up using a pair of normal pliers. Despite having loads of tools for plumbing and leccy work in the UK I could not find a pair of pliers on the first day I was doing this work. I was using needle nose and could not get enough force without causing too much pain in the fingers and palm... Off to screwfix and the job was done in a few minutes. but then, when I came to replace the rear shoes a few days later, there was one spring that was just a b***er. not sure whether the teeth on the pliers had gone, I was knackered or whatever. But it kept slipping off and I ended up losing the nice shiny cap in to the ninth dimension as it sprung back, missed my bulk and zoomed off in to some brambles. Thankfully I still had the old caps from before I replaced the springs. If I do this job again I will definitely buy a spring puller and a the spring washer tool.

Yes. Handbrake operates on drums. I don't think it is the cable in my case as I can pull the cable quite freely from inside the cabin. But when I get back I will check the cable just in case.

thanks, that's really useful.