ABS diagnosis/check procedure

[ginge191]

Changed the rear beam today on the GTI with the help of Vlj, Samass, Scott and Jonny11026581639461 but before (on occasions) and after the beam was changed, the ABS light stays on and doesn't work when coming to an abrupt stop.

What's the best way to diagnose/fix the problem.
The plugs on the rear end are intact and clean; these were changed/checked when the beam was changed.

Jonny did have his computer but unfortunately ran out of juice, would it be an idea/essential to plug it in to find the fault?

Any ideas/checks are welcomed x

[MartinL]

Would be best off plugging it in, theyll be a code saved but if you have a multi-meter.. you can stick it on ohms and check the sensor to see if ita faulty i presume

[ginge191]

Would be best off plugging it in, theyll be a code saved but if you have a multi-meter.. you can stick it on ohms and check the sensor to see if ita faulty i presume

..and check for a contant feed; this i assume on the plugs themselves?

[Niall]

no. Just no

A WSS will create vAC when the wheel is spinning. Get a multimeter across both terminals set to vAC and spin the wheel. you should start to get a fluctuating voltage. Now compare to the other side. No voltage = dead sensor. If it only happened occasionally, id be inclined to think damaged wiring somewhere as rarely do these sensors go wrong then start working again.

---

oh and btw you will have to do that on all 4 wheels. If its just the rear wheels locking, it will be a seized compensation valve seeing as your ph2 has ABS instead of EBD like on the ph3s.

[ginge191]

no. Just no

A WSS will create vAC when the wheel is spinning. Get a multimeter across both terminals set to vAC and spin the wheel. you should start to get a fluctuating voltage. Now compare to the other side. No voltage = dead sensor. If it only happened occasionally, id be inclined to think damaged wiring somewhere as rarely do these sensors go wrong then start working again.

---

oh and btw you will have to do that on all 4 wheels. If its just the rear wheels locking, it will be a seized compensation valve seeing as your ph2 has ABS instead of EBD like on the ph3s.

Apologies in advance; vAC?

[Niall]

Ac voltage. Sorry. I'm in essay writing mode so writing everything properly lol

[ginge191]

No worries; and the terminals; which terminals am i wiring the multi-meter up to?

[Niall]

Unplug the abs sensor you want to test and it goes over the two pins for that sensor.

[ginge191]

Gotcha

Are front sensors easy to find; plugs for the rear's are pinned up on the chassis behind the spare wheel, front's i've never seen

[Niall]

Take the front wheels off and you will see them. The plug for the drivers side is up in the engine bay next to the master cylinder. Grey 2 pin plug. Clipped to the inner wing almost opposite the exhaust cam. Passenger side is a bit of a pain. It's behind the battery box right down the bottom. Grey two pin plug again clipped to the inner wing.

[ginge191]

righty; i'll have a pop on friday when vaughans over; we're gonna have the front apart anyway to fit some coilies

Cheers babe; usual, expect a call at some point

[4WayDiablo]

I have a decent multi Meyer and tom has pug planet if that's of any help?

[MissTap_GTI6]

I have a decent multi Meyer and tom has pug planet if that's of any help?

Yeah that could be very useful

The light goes on and off intermittently.... :/

[Niall]

Eli im bringing my Fluke and pug planet. So basically, f*ck you Phil!

[4WayDiablo]

Ohhkaaayyy

[aggyj17]

no. Just no

A WSS will create vAC when the wheel is spinning. Get a multimeter across both terminals set to vAC and spin the wheel. you should start to get a fluctuating voltage. Now compare to the other side. No voltage = dead sensor. If it only happened occasionally, id be inclined to think damaged wiring somewhere as rarely do these sensors go wrong then start working again.

---

oh and btw you will have to do that on all 4 wheels. If its just the rear wheels locking, it will be a seized compensation valve seeing as your ph2 has ABS instead of EBD like on the ph3s.

Would I be able to test the rev counter sensor this way on my xud??

[Niall]

I think it works the same way but not 100% sure. Never had to test one mate.

[Ruan]

If it's intermittent, you may find all the sensors are outputting fine, you'd need an Oscilloscope to actually see what's going on, a multimeter won't give you that snapshot in time that a scope can...

If you can't instantly pick the fault up with a meter, just get it plugged in, you could be shooting in the dark for a very long time...

Judging by the fact the new rear beam hasn't changed any of this to being either on 24/7 or fixed completely, I'd put my money on it being a fault with a front sensor... Check those first.

[ginge191]

Judging by the fact the new rear beam hasn't changed any of this to being either on 24/7 or fixed completely, I'd put my money on it being a fault with a front sensor... Check those first.

Gotcha neil is round at the weekend with his doctorate tools to fiddle with some wires and work his electrical (bodge) workmanship...