Voltage/resistance readings at abs wheel sensors?

[scabbyscala 0]

Corrado 2.0 16v 1993 (brothers car)

 

Hi peeps,usual ABS light on in dash - wasn't on before i carried out the following : replaced rear bearings, discs/pads all round, full suspension and sundries allround, cv boots, full service+.....etc.

 

I bought a Mitchell On-Demand Service Guide CD for the VW group from an Ebay seller a few weeks ago and used it yesterday to follow the recommended brake bleeding system in it but it didn't work - perhaps this is related to ABS light problem.

 

The method of bleeding i followed was to position the rear brake balance valve lever thingy (nr rear beam) towards the rear of the vehicle , get my assistant to place pressure on brake pedal and turn ignition on as i open the rear bleed nipple to use accumulator pressure to bleed rear, then after a few seconds close bleed nipple , switch ignition off and release brake pedal.

 

Did this and followed the instructions to a "T" but no fluid came out (well...only a dribble), so i checked to see if the pump was running when the ignition was switched on but i couldn't hear it and i noticed the light was on in the dash.........I'm 99% sure the light wasn't on before i started the b-bleeding procedure as i had the car started up and running as i'd just changed the oil/filter and wanted to check levels after warm up, i was sitting in the car when it was running so i would have noticed the ABS warning light.

 

Got the glovebox/undertray all stripped out and located fuses (30amp) and both relays (79 + 179) , the fuses are fine but how do i check the relays? and what are the correct voltages at the multiplug for the ABS ECU so i can check this and possibly fault trace using a multimeter.

 

The Mitchell service guide only shows a two row ecu connecter block and corresponding voltage checks but the one on the Corrado is a three row Connecter block so i dont really want to be sticking my multimeter in the corresponding pin holes in case the layout is different.

 

If anyone can help with info relating to checks for the relays-voltage/resistance, and an ECU-voltage/resistance checklist for the ABS connector block i'd much appreciate it as this is the only thing stopping the car getting through it's MOT.

[dr_mat 0]

There's a quicker and easier way to diagnose ABS problems... VAGCOM/VAG1551 error code readers. Any decent VW specialist should have the facility to read ABS error codes.

[scabbyscala 0]

tafkadm : The car's mot has ran out and the nearest vw dealership is 35 miles away - If i was stopped by our friends in blue (friends?.....aye right!!) do you think i'd get grief from them for not having an mot? - The car is taxed and insured.

 

What should it cost (approx) to get vw to plug into ABS ECU and retrieve error codes? - I took them a big box of M&S choccy bics last week for advice/help on the VR6 topmounts and engine stuff for my GT11, so hopefully they'll be accomodating on the VAGcom check - might get them to do the mot as well.

[dr_mat 0]

They *usually* charge half-an-hour labour for a diags scan, but that's discounted against the cost of any repairs that they carry out. You might get away with less, since you appear to have a good relationship with your local dealer, but most people can't claim that round here..

You are allowed to drive on the road with no MOT providing you are ON YOUR WAY to getting it done.

For a quick check, the resistance of the wheel sensors should be around 2k ohm. Much lower than a few hundred ohm or much higher than 10k ohm and you're got a fecked sensor. There *are* detailed test procedures that can be carried out to work out which component is faulty, but they're not documented anywhere other than the factory repair manual (£60 from amazon), and to be honest the ABS ecu has already done that for you, so your best bet is to probe it off the ECU.

[scabbyscala 0]

It's booked in on thursday to get the ECU probed (ouch!-sounds painfull) , so will post the results on here incase it helps anyone else out at some point in the future.

 

Camber/Castor & tracking getting done on friday then it's MOT time and finally a blast round the deserted b-roads to see if it all works as it should!.

 

 

Freakin hope so!.