Mk5 ABS Module Failure, DIY repair??

You only need do a search on mk60 brake pressure sensor/transducer to see that it is a big/common problem.

 

Exactly Gary, not hard to find yet they still deny any knowledge lol

 

Well, I fitted a brand new VAG repair kit at 150 and the ABS pump side of things is sorted, although bleeding the things is an absolute nightmare even with Vagcom. Over 4litres through the system and it's still spongy with excess pedal travel, well more than I like to have.

I also had to change 2 rear sensors and rear hubs (rings are part of the hub) But......
I'm getting inaudible signals from both rears though which is pulling up the ABS light again. I'm hoping it's just a 'gapping' issue with the sensors standing proud.

I did manage to get the car through an MOT as I could cancel the codes long enough without them re-appearing. It'll give me chance to run the car and see whats going on.
I'll feedback with the results when/if I get some!

 

Once you've done the initial HCU purge with VCDS/vag-com it should bleed easily Mart.

http://www.ross-tech.com/vag-com/cars/absbleeding.html

VW have a pressure bleeder that's used on servicing to change brake fluid, with that on never had an issue bleeding them.

Don't know how you've done it but I always beed furthest from m/c first say right rear, then left rear,left front,right front.

Is there any rust in the bores where the rear sensors sit making you think they're sitting proud/excess air gap?

Does it show up the rear wheel speeds in the live data measuring blocks on vag-com?

Just hoping you don't have an ABS controller fault as the mk3s do giving spurious rear wheel speed codes!

 

Evening Gary,
its bleeds easily enough, but it feels like there's air in there somewhere. I've used both the pressure bleed direct from the nipple, to the '2 man' technique. Everything looked nice and clean when I replaced the ABS pump unit. The module is from an Audi that I coded to the car.

As for rust in the bores, theres more rust than bore lol. I'll take them out and clean them thouroughly. Any idea what Group is usedfor the wheel speed, and can
I just spin them by hand to get a reading?
I did look through some of the measureing blocks and one (not sure which one) was giving a wheel speed of 256kph for each wheel. This hasn't changed since owning the car or changing the Module/pump unit. I'll have a good look tomorrow evening

 

Sounds like air in there somewhere mate, tried clamping off a flexi and see if pedal feel improves?

Without looking I don't know the groups for the wheel speeds, but if it's showing 256kph when stationary, that's why it's giving an implausible signal fault code I would say. (If thats the right block you're looking at of course..)

Once you find the groups for all wheel speeds I'd check them on road test whilst viewing the data so you can compare at say 30mph/50km/h, you can spin them up on a jack and it should show..But I'm lazy.

If it was an air-gap problem I would expect your fault description would be 'mechanical fault/malfunction' rather than implausible signal.

 

Looks like you want ABS [03] group 01 for the wheel speeds,
group 02 will show the 255kphs (Why? Dunno)

 

All sorted. Bit of a b'stard but all done.
I found that my steering angle sensor wouldn't respond which was all down to a duff new rear abs sensor. ONce that was changed the sensor started work, the lights on the dash went out and without any coding thre power steering kicked back in!