ABS fault - Intermittent. 9N3 GTI.

Hello,

I know there is a lot of threads on ABS and sensors but I guess every problem is unique, I have a 9N3 1.8T Polo GTI (07).

A while back my ABS light had come on along with traction control permanently off, scanned the car and it came up with:

''ABS Wheel Speed Sensor Rear Left (G46), 008 - Implausible Signal - Intermittent'' 

I investigated and found some of the wiring had burnt through the exhaust but was soldered (badly) by the previous owner, I unplugged the sensor and pulled it through the car onto the rear bench, cut the bad solders off, stripped and crimped (upon inspection of the wiring the black was slightly discoloured, maybe from the previous owner putting too much heat on the wire), this worked fine for around a day of driving. Then the fault seemed to reappear, I again pulled the cable through the car, checked the wiring and repeated the same process, still didn't work. I then cut the crimps off and soldered. Now it seems the problem is very intermittent, the fault comes and goes very quickly. Sometimes it's on for a day then other days vanished and everything works fine.  

An output test for the ABS was also completed via VCDS when the fault was gone and everything checked out fine. Measuring blocks whilst driving shows no output from the rear left when fault is present.

As I'm typing this I realise this looks very much like a wiring fault but I can't help thinking this may be something else. So far I've changed the sensor, the rear disk has also been removed and cleaned up any dirt maybe stopping the sensor from working correctly. My next idea is to maybe change the rear wheel bearing as it works with the sensor to output a signal. 

Any thoughts, similar experiences or little things I can check would be appreciated. 

Thanks,

John