How can I test a rear wheel ABS Sensor off the car.

My LH rear sensor has an implausable signal, is it possible to test the item off the car because I have read in loads of threads that replacing with a new unit sometimes does not cure the problem.

Any help appreciated.

DB.

It's a Hall Effect sensor, so no, it cannot be tested off the car, unless you have an oscilloscope, regulated power supply, and pin out arrangement of the sensor plug, and a magnet.

It's a Hall Effect sensor, so no, it cannot be tested off the car, unless you have an oscilloscope, regulated power supply, and pin out arrangement of the sensor plug, and a magnet.

+1

You can check the ABS ring for missing/damaged/corroded teeth, the sensor has the correct gap to the ring and you can check the wiring/connector for damage.

Is it worth it? Given that 95% of the time it is the sensor, then I would say not.

Thanks for your replies.

The ABS light only comes on after 500 metres and cancels itself out when the ignition is switched off.

On VAG COM it shows a fault code of 00290 - Rear L brake - 008 Implausable Signal Intermittent.

I was trying to determine whether it's the Sensor or Wiring.

DB.

implausible = sensor. Wiring would be "+/- open/short to B+" or something along those lines. Plus it wouldn't reset - it would be permanent

If it's not the sensor...it could be the reluctor ring on that hub unit which has a "dead" spot. Had this problem on my fronts a few years back!! Thing is the reluctor ring on a Fabia is part of the hub/bearing unit...so not exactly cheap!!! First thing to do is clean to reluctor ring (orangy/brown coloured rubbery ring on the back of hub) with a cotton bud and meths to get the crap off.....if that dosn't work and you've replaced the sensor and the wiring is ok..then it is the reluctor ring!!!

Im sure i got a new bearing with ring for the rear for £80 ish

Genuine part and was a doddle to fit

Thanks to all, especially Nick from Alsager who diagnosed the ABS problem at the LH rear sensor with his VAG COM.

I followed the info supplied via the Briskoda thread, removed the rear hub, using meths I cleaned off the solidified brake dust from the reluctor ring, re-assembled with a new nut and hey presto the ABS light did not re-appear.

Thanks again.

DB.