ABS coding after upgrade

[Pierlu]

Hello everyone, I've just updated my brakes from 256mm front and 232mm back to a simil Audi S1 configuration (312mm front, 272mm back)

The mechanical part is ok but I've encountered issues while coding the ABS with VCDS.

Code: Select all

Address 03: ABS Brakes (J104)       Labels:. 6R0-907-37x-ESP90.clb
   Part No SW: 6C0 907 379 K    HW: 6R0 907 379 BA
   Component: ESP9.0i       H03 0004  
   Serial number: 08503816150928
   Coding: 21DD2885492533C40914106F0052841492CC90080005CB098F00
   Shop #: WSC 00788 648 00255
   ASAM Dataset: EV_Brake1ES9P0iBOSCHPQ26 100020
   ROD: N/A
   VCID: 377C13408E4D85FE7B-8063

No ASAM data for: "EV_Brake1ES9P0iBOSCHPQ26" (VW26) 
No fault code found.

This is my actual scan, is a 2015 Polo 6C.

I was trying to use the S1 values for byte 2 and 15 but the code is rejected

21 DD 28 85 49 25 33 C4 09 14 10 6F 00 52 84 14 92 CC 90 08 00 05 CB 09 8F 00 (mine)

36 DF 70 8B 8D 28 33 C4 49 18 30 6E 00 57 6C 0E B1 CC 92 0C 00 13 E2 09 0F 00 (S1)

I've not understood why I cannot reuse these 2 values on my coding (70 inverted is 0E so this should be ok)

Thanks in advance

S1 ABS Scan

Code: Select all

Address 03: ABS Brakes (J104)       Labels: None
   Part No SW: 6C0 907 379 S    HW: 6R0 907 379 BA
   Component: ESP9.0i       H04 0006  
   Serial number: 08503318161103
   Coding: 36DF708B8D2833C44918306E00576C0EB1CC920C0013E2090F00
   Shop #: WSC 00046 412 00000
   ASAM Dataset: EV_Brake1ESP90iBOSCHPQ26 100020
   ROD: EV_Brake1ESP90iBOSCHPQ26.rod
   VCID: 3F8D53C6A6C768BA97-806A

No fault code found.

[iichel]

It's the same reason why I can't code my Polo 6R to WRC brakes; it checks the brake size and the engine bytes. If they don't match, it will reject coding.
I don't think it's possible, sorry.

[Jay-Jay]

It doesn't accept it, because it needs you to modify the bytes of car type, transmission and engine too.
I analyzed the long coding of my S1 and I tried multiple times to insert the correct bytes into the ABS unit of a 6C GTI with BBK, but without success.
So, I guess there is some other software limitation.
Maybe, since there is no Polo with that brake configuration, the ABS unit is not programmed to recognize it, even if tou try to fool it that you have an S1.
The only thing I suggest you to do is to insert the coding for 288 or 312 front and 232 rear.

[Pierlu]

It's the same reason why I can't code my Polo 6R to WRC brakes; it checks the brake size and the engine bytes. If they don't match, it will reject coding.
I don't think it's possible, sorry.

this is a terrible news

It doesn't accept it, because it needs you to modify the bytes of car type, transmission and engine too.
I analyzed the long coding of my S1 and I tried multiple times to insert the correct bytes into the ABS unit of a 6C GTI with BBK, but without success.
So, I guess there is some other software limitation.
Maybe, since there is no Polo with that brake configuration, the ABS unit is not programmed to recognize it, even if tou try to fool it that you have an S1.
The only thing I suggest you to do is to insert the coding for 288 or 312 front and 232 rear.

I've tried for hours without success, the 288mm coding is accepted but the GTI not because I've not understood which bytes I have to change on a 6C to create a workaround during the coding, a 312-232 should be fine, ok not the same as S1 but a good compromise (I think)

[Jay-Jay]

Theorically, 288/232 coding should be more similar to 312/272 coding in terms of hydraulic brake distribution.

On my Polo I have 312/272 brakes with 288/232 coding and I am pretty satisfied with it.

The main principle is:
"the bigger is the disc, the lower is the pressure".
This to avoid wheels from blocking too early and engaging ABS too early (which would neutralize the benefits of the brakes upgrade).

In the end, if your ABS unit doesn't accept the specific coding you need, you can modify the brakes to restore che correct brake distribution or at least try to get as much closer to it as you can.

[Pierlu]

Yes, at the end I think I'll stay with 288/232 coding (at least the front caliper piston have the same dimension as 312mm brake configuration). Due to the quarantine I've not tested the brakes so I don't know at the moment if are ok or not

I don't want to write nonsense things but if exist a "ratio", yes this coding should be better than the stock one

256/232=1,103
312/272=1,147
312/256=1,218
288/232=1,241
312/232=1,334


Now, I'm not a mechanical engineering (only a computer one) but if could exist a mechanical correlation, maybe the 288mm coding should coverage all the configurations with large disks on the rear axle (or maybe not, how knows). Of course this is only an idea and I'm not interested at the moment to go back to 256mm/232 (I'm planning to upgrade on 312mm brembo calipers )

[Jay-Jay]

I prefer to calculate the difference between front and rear discs diameter for better understanding the braking force difference between front and rear axle (even if it's not a correct procedure , since there are many other factors to consider, like piston's diameter, pad's dimension, etc.):
256 - 232 = 24
288 - 232 = 56
312 - 232 = 80
312 - 256 = 56
312 - 272 = 40

The 288/232 difference is the closer to the 312/272 difference, so I guess their respective codings could be similar too.

[Pierlu]

Yes, at the end the result is similar. I have only to try everything asap

[arturbo]

Friends I have a problem with my ABS from one moment to the next after a change of ECU the coding of the abs appeared completely in zeros, someone could help me is a polo gti 6c