ABS sensors and no ABS Light!

[chilli_dub]

Having vagcom'd the car its returning three ABS sensor faults. Changed one of the fronts yesterday, what a headache that was, took some serious effort to get the old one out and new one in. Finally got it in and connected to discover the tip of the sensor is actually making contact with the ABS ring! Surely this cant be good? The wheel still spins freely. Is this okay? Or is the sensor dodgy? Got it from GSF.

Another issue is the ABS light. Its non existant. Ive taken the cover off and the bulb is fine, no issues there, what else could be causing this to not light? The ABS system must be active for vagcom to return these faults surely?

Any input would be greatly appreciated, thanks.

[Mikester]

the system doesnt have to be active to return the fualts, as they are stored on the ECU when the fault first occured.

So there for you could have had a more serious problem since then. But that dont explain why the light wont light up as that shouldnt be related.

Have you checked all of your fuses? And i believe there is an ABS relay too.

[chilli_dub]

Right, just been out and had a look. There is a metal fuse for the ABS that i have removed and tested, this is working fine. There is also a relay for the ABS, is there any way of testing this? The bulb is 100% working so there is no issue there just not getting 12v across the terminals.

[harlemex]

Your abs sensor should not be in contact with the ring. GSF must have given you the wrong one as its too long. I fitted one to my car the other day, there is only so far that it goes in and once flush, it is not touching the abs ring. Not sure about the light though....

[chilli_dub]

Right, im ressurecting this thread! Ive now changed all the ABS Sensors so there is no longer any ABS faults showing at all, however my ABS light refuses to work. My car is a mk3 16v 97 so the ABS ecu is located underneath the pump in the engine bay right?

Another thing is that the ABS doesnt work! When braking very hard i dont get any feedback through the brake pedal at all. Would this be a fried ABS ecu or a knackered pump or both?

This is really pi**ing me off. The cars in for its MOT this weekend so need to get this issue sorted out.

Any input would really be appreciated, anything left to check?

[Mikester]

If the ECU was broken i dont think you would get the fault codes for the sensors.

And if it was the pump im pretty sure it would show a fault code for it?

My abs works 100% ok, but i do have to really be braking some for it to kick in, when its dry. Only ever happened once in 3 years.

Does the car skid when you brake hard?

[chilli_dub]

Thanks for all the input it all helps

An update on the non-existant light. Total frustration led me to do some serious tinkering. Ended up removing the fuse box to discover that someone had cut the signal cable that goes into the back of the ABS relay and bridged it with the live wire so that the light never came on!! How bad is that?! So after a few mins with some connectors and tape i now have a working ABS light!

Thanks for the input. Right I have had the car rescanned and it is showing a rear ABS sensor (obviously installed a duff one or the ABS ring is knackered) and is now showing an ABS pump fault I have done a lot of research and it appears that sometimes a knackered rear sensor can flag up an ABS pump fault. So im going to go ahead and replace a rear tomorrow and fingers crossed it isnt the pump! Atleast im beginning to get somewhere with all of this.

I dont know why im so desperate to get it working, ive never really had any issues. It will just be nice knowing everything on the car is working 100%. The car does lock up but i have to be braking seriously hard to get the wheels to lock. I guess it would just be nice to know its there incase i need it.

[Mikester]

I have replaced some of my sensors more than once, the rear ones too. I think that the cheapo GSF/ECP sensors are not much cop.

[mush]

yep completely agree the ABS is a pig to sort out, specially when everything’s ceased up. just one point on the abs rings I would check it hasn’t come loose from the back of the disc or broken up when trying to get to. also might be worth just getting new ABS rings only £8 or something like that from GSF. my abs rings where shot and I wasted a lot of time just taking them back off again :-(

anyway I hope you get things sorted its your mission to get this fixed.

if its any consolation my ABS lights back on but its just a sensor so unplugged the dam thing now until I can be bothered to sort it 

[Pete Taylor]

I've had the pump fault show up before, it went away by itself after softing the sensors.. so there's hope!