Checking ABS

[toddy98274]

Hi All

I have a Mk3 8v AGG engine which is due for its MOT next month and true to form something is playing up.

The ABS light on the dash is staying on sometimes (but not always) and this usually happens in the rain or when the roads are wet.

I was thinking maybe this could be the sensors and parts by the wheel getting clogged up after its bee raining?

Might be a long shot but could anyone explain to me how to check the ABS sensors, ie where are they for a start and also explain if I need to check any other parts that I can do myself simply by taking the wheel off.

Other than that I can only think that I have a faulty sensor that will need changing but I would rather have a look myself first if possible before my local dealer decides to change all the semsors anyway even if they dont actually need replacing!!

Any help is appreciated

Thanks

[adyh]

Easiest way to find out what is wrong is to get your fault codes read . As the problem is not constantly there the problem will be listed as intermittent .

[raylee25]

take your car to your local vw dealer, tell them that the ABS light is on, but the manual says refer to dealer. They will then plug their computer in to your car to reset the fault and also tell you which sensor is faulty.
Once you know which sensor it is, it will take about 1 hour to do. its easy to do. But get the sensor for GSF as its miles cheaper than the stealers.(around £20).

[boneybradley]

if the dealer want's to charge you for putting on their computer..don't bother as you can but a decent fault code reader on ebay etc for about £30 which can read codes on engine,airbag and abs.. just remember if it has a port (next to the front ashtray) it's obd2 or if not it's obd1 which is located in the foot well.. or you can but a laptop vag-com cable

[AudiA8Quattro]

Don't bother with any of the above.
Buy a cheap multimeter instead, unplug each sensor and test for resistance.
Faulty sensors always come up no continuity.
Money is on o/s/f sensor 

[toddy98274]

Hi All

Thanks for the replies so far

One more thing is that if i do go down the diy route as suggested, what do the actual sensors look like and where abouts do i find them once the wheels are off?

The light hasnt come on at all since I posted yesterday which is odd, will the fault still show up when linked up to a fault system if I do end up taking it to a dealer?

Raylee25:  Any suggestions for a reliable but cheap fault code reader off ebay, I have considered buying one in the past but didnt really know how good they were at actually reading the faults and giving any useful info.  Id love to have a vag-com set up but unfortunately i dont have a laptop or cable!!