Abs pump/module problem VW passat B5

[The jag man]

Hi chaps,

Going to need a hard-core Vdubber for this problem I think.
Problem is as follows: spongy brake pedal.
3 garages cannot bleed it successfully so I'm not just being soft
There is no other issues, no abs lights on the dash (most of the time, I'll explain later) the car stops but the brake pedal feel is awful. I've thrown a genuine brake master cylinder at it as well.

I've seen that sometimes you need to bleed the abs pump via VCDS/vagcom to purge all the air out so I have got a cheapo cable and a registered version of VCDS lite so I can manually run the abs pump so I can bleed the brakes this way. The problem I am now encountering is when I connect to the abs module I read the codes and get code 65535 "internal module memory error'. I then go to run the output tests and it immediately will say its done it (which it clearly hasn't) then I press it again and I get "no response from controller''. At this point both the abs lights come on the dash which then go away when turning the car off and on again. I can't hear the abs pump running or any clicking etc. To check the cable is working I went in to the engine module and ran the tests and these tests worked as expected with the relays clicking, fan coming on etc. So no problem with my software communicating with the module.

At this point I am thinking of getting a 2nd hand module and trying that but I don't like the idea of buying one second hand and definitely don't like the idea of buying a new one. Second option would be a refurb of the module for like £120 but I really don't like the idea of continuously throwing money at a problem without a bit more confidence I'm going to fix it properly.

Any previous experience or advice would be HUGELY appreciated as I am determined to get to the bottom of this.

Thanks in advance

[Polly Grigora]

Does the ABS work?

[S6PNJ]

Where in the UK are you located? There might be a friendly (full) VCDS owner nearby. Have you registered / asked on UKPassats forum? They might be able to help. http://www.ukpassats.co.uk/phpbb/ Sadly the VCDS map link on there no longer works.

The jag man said:

....stuff....So no problem with my software communicating with the module.

I've found that VCDS lite won't always pick up fully all modules etc. So just because it links to the engine module, doesn't mean it will link to the ABS module (fully).

I used to have a B5.5, sold it last year and got a B7 - had an ABS issue with the B7 which initially directed me towards changing the ABS module, but I did a bit more fault finding and realised I'd been sold a faulty sensor, so when another sensor was tried, my fault cleared and I didn't need to swap out the ABS unit (initial fault directed me to the sensor but after chaning it, the fault didn't clear). With my unit (and probably with the on on the B5) you can separate the electronics from the valves as long as you can work out which bit is (or might be) at fault.