Had a problem with spongey brakes per my earlier thread :

fabia 1.2htp brakes still feel spongey after being bled - Skoda Fabia Mk2 (2007-2014) - BRISKODA

However, a new problem has occurred with symptom that ABS light is now on permanently. Brake feel has much improved, however, vehicle won't get through MOT with ABS problem. Before any says, yes I know there are workarounds that might get the vehicle through MOT, but it would be good to resolve the issue properly if poss, and restore the ABS function.

Have connected VCDS and there is no comms with the ABS module, so ordered a replacement one (from breakers as they are unobtainium otherwise), Part number is below, it's same as the OE unit that is in the car currently.

6R0 907 379 S / 6R0 907 379 AB

Plugged this replacement module in to the harness yesterday, just to check whether OBD now works, and still no comms with the ABS controller, and ABS light still on. I would have expected at least to see the ABS controller with VCDS.

So looks like could have a wiring fault , in addition to anything else that might be wrong, and wondering if anyone (@Breezy_Pete ?) has a ABS wiring diag for this car (2010 mk2 fabia 1.2 htp, can supply VIN etc if needed) so we can buzz through and check connections.

Checked fuses but there could be more than the 2 we have checked (25A one in engine bay and 5A in the interior fuse box).

Any other pointers gratefully received !

I was thinking as next step hooking up the replacement ABS unit to VCDS and 12V power on the bench to see if if the replacement unit works, it came with the harness connector connected to a short length of the harness.

thanks muchly

@Breezy_Pete you are inadequately tagged above 😉

But.. have you checked the reluctor rings on the hubs? They often fail or could be misaligned after your brake replacement, so it may not be the controller.

Thanks mac, was busy outside washing cars!

ABS rings are integrated into wheel bearings on these, so pretty robust against damage.

@abba you have made enough posts to open up messaging, so please let me know the VIN, for working out build date and ABS type, by private message.

thanks both, I wasn't sure how to tag. Will PM the VIN to you Pete when I get/ find it - may already have done this when we had the issue with the fuel pump when you kindly supplied fuse/ wiring info (car is a bit of an odd ball) . I don't recall if I messaged you then with the info or just posted it (will see if I can check back).

I have now buzzed the connections on the harness connector that came with the replacement (via the short length of harness fitted).

17 out of the 38 pins on the Delphi connector are populated. If the PNs are the same, I assume it will be the same on the actual vehicle ??? Wiring diag will tell all.

We need the controller working with OBD 1st to see any faults with the wheel sensors etc. We don't seem to have any comms at the moment, with either the ABS controller module in the car or the replacement when plugged in to the vehicle harness. (We can see the engine ECU fine).

thanks

PS I have just checked, VIN PMd to you 16 Sept 23 Pete, do you want me to resend ?

Edited 8 March8 Mar by abba
add new info (PS)

Four fuses in total.

Fuse 7 (25 amp) and fuse 10 (40 amp) in fuseholder A (battery top one).

Fuse 4 (5 amp) and fuse 48 (15 amp) in cabin fusebox.

all except the 5 amp one are permanent 12V feeds; the 5 amp one is ignition switched.

Will reply to your PM with a circuit screenshot, to help with pin numbering of all of these feeds.

Sons MK1 was the same. ABS/brake warning light. On his it was the strip fuse beside battery that had a hairline crack. His brakes were also spongy and needed a pressure bleeder to remove air from rear after piston replacement. Tried manually for ages but only when I used a presurised gunson the air came out.

Alasdair

Theoretically, if you replace the ABS module, you need the long coding of the original module in order to know which options the car is equipped with. The module is also linked in part to the VIN. Once you disconnect it and try to connect another one and switch the ignition on, most probably you will lose the original coding.

So I hope you did an autoscan with VCDS (it saves the coding on your PC). The same thing happens if you remove the original cluster and plug in a new one without coding it first (ask me how I know, haha).

Basically, once you figure out your ABS issue, you will most likely need to code it back.

Edited 9 March9 Mar by Jack25

The key to effective bleeding of the rear wheel cylinders, I think, is to do so with the rear beam at its normal working angle.

If you look at images of people doing stuff to rear drums with the beam hanging down in the position it falls into when jacking just on the bodywork, the wheel cylinder tilts at same angle as arms of the beam.

That results in the cylinder being at an angle to the horizontal. The bleed nipple is central in its length, so an air bubble can sit above and beyond the entry point of the bleed nipple, like a bubble in a tilted spirit level.

thanks for those comments.

Alasdair - yes, we have got a gunson eezi-bleed (same m/cyl cap on the T4) and used it last time we bled the brakes. When we rebleed we will check for beam position (Pete)

checked the fuses on the battery I know the style you mean and which seem prone to aging/ hairline cracks, but they appear more robust on the Mk2 and cant immed tell if blown, as they are encapsulated, but DVM indicates all are intact.

Jack - interesting - not sure wanted to read that but thanks ! if we reconnect the original one and switch on would that work ?

what tool do we need to do all this - VCDS lite isn't up to the job we now know as it would appear ABS uses CAN. Full blown VCDS looks expensive - is there a cheaper alternative diag tool that will do what we want (e.g. ABS scan for faults, ABS bleeding and recoding modules if reqd). And, no, we didn't do an autoscan, as we don't have full VCDS at present. Like you, finding out the hard way, ha ha !

I belive there is a good possibility to be trouble free when you will plug the old abs module back, online you can find the decoder of the long coding, currently I have to test a new one to see if it does work, if it does i will link it here so if there is any problem you can get your long coding back.

Is not a good thing to say but you can find full vcds software on aliexpress, they will send you the file/online dowload and you will be good to go, i use that and i'm able to do everything

Not quite sure* atm what you mean by 'online you can find the decoder of the long coding', but many thanks Jack. What interface would I need, currently I have one from Gendan that we're using with VCDS Lite, but it is a KKL interface hence K-line only I believe and not CAN capable ? It reads the engine / ECU module but not ABS.

* ok I have just googled that - now I have a better idea about VAG ABS long coding ! Every day is a school day.

sorry for my english, you can find charts like this one:

You will need also a HEX-V2 interface, if you go the aliexpress route be sure to turn off the wifi or internet connection on the pc, every time the HEX-V2 interface is plugged to just the pc or the obd port (and the pc), otherwise the HEX-V2 will recognise the non original version of vcds and update the cable software making it unusable.

(the chart works fine for my long coding i have abs/espp 8.2i exep after the 16byte i have additional 00 so maybe try to add it too)

Edited 10 March10 Mar by Jack25

thanks for the advice Jack, there's nowt wrong with your English btw ! just my understanding !

You're welcome, thanks!