Can someone please post what their byte 4 and 17 in the brake module is (the hex)?

[krs]

I ask you about this previously in your 312 post and you were going to look into it. Finally figured out how from @DerHase on the 17 being a mirror etc. and how to do that with hex to binary etc. OBDEleven was giving me fits but figured out how to do it finally in the long coding...have to change both 4 and 17 at once for it to accept the coding change...set mine to 370

So if I’m running 370mm front brakes, is there value in changing this alone?

 

[golfdave]

So if I’m running 370mm front brakes, is there value in changing this alone?

It has to altered in two different lines (bytes), if you just alter one line (byte) it doesn't like it & rejects the coding...been there & done that....which is why I gave up years ago! But having others successfully try it by correctly altering both bytes I'm having a play with VCDS later this week...


For 370mm front brakes you should state "C4" in both Byte 4 & Byte 17

 

[tigeo]

It has to altered in two different lines (bytes), if you just alter one line (byte) it doesn't like it & rejects the coding...been there & done that....which is why I gave up years ago! But having others successfully try it by correctly altering both bytes I'm having a play with VCDS later this week...


For 370mm front brakes you should state "C4" in both Byte 4 & Byte 17

For 370 it's C4 for byte 4 and 23 for 17. 17 is a mirror of 4 (not the same value)...convert C4 to binary, then reverse it, then convert back to hex. For 288s it happens to be 24/24 the way it converts.

 

[tigeo]

So if I’m running 370mm front brakes, is there value in changing this alone?

No idea. This is the whole thing where we don't actually know what most of this crap does/all speculation. I figure why not. I'm running a 350 BBK vs. 288s my car came stock with so did 370.

 

[anotero]

So if i upgraded to PP front rotors, i should change the byte value? And if so, then to what as there are 4 340mm options?

 

[Cuzoe]

@anotero I guess we don't know for sure but...

I looked at as many Golf R scans as I could find when retrofitting EPB to my Golf and 54/2A is what I saw most often.

Here's my long coding with Bytes 4 and 17 bolded, from my 2017 MK7 R
01FA6BA154240975457E030140C36980D62A90A2C00296373440508440A8430000000012121212B835351919323200

Fixed the original error to avoid future confusion.

 

[golfdave]

For 370 it's C4 for byte 4 and 23 for 17. 17 is a mirror of 4 (not the same value)...convert C4 to binary, then reverse it, then convert back to hex. For 288s it happens to be 24/24 the way it converts.

@Cuzoe ...

So trying to do my ABS module & there are no tick boxs in VCDS basically VCDS say phone support..so its all enter coding manually....my Byte 23 is for the lower spec cars (upto 110kW)...& states "F3"....so to change it to the 132kW to 155kW is what ???...if there were boxes I would just uncheck bit1 & check bit2...

 

[Cuzoe]

@Cuzoe ...

So trying to do my ABS module & there are no tick boxs in VCDS basically VCDS say phone support..so its all enter coding manually....my Byte 23 is for the lower spec cars (upto 110kW)...& states "F3"....so to change it to the 132kW to 155kW is what ???...if there were boxes I would just uncheck bit1 & check bit2...

You have to enter the coding string manually.

So for the change to byte 23 you would change byte 23...
From: 04FA8AA12425296E0380060941C82920512494C0608294F3F4205078C009
To: 04FA8AA12425296E0380060941C82920512494C0608294F7F4205078C009

Edit: I incorrectly suggested F7 here, should have been F5 for @golfdave with 135kw...
Bits 1 and 2 of Byte 23 are for XDS, info from Somnus ABS Spreadsheet

Bit 1 & 2 unchecked	XDS OFF
Bit 1 checked	XDS up to 110kw (147hp)
Bit 2 checked	XDS 132/135/155kw
Bit 1 & 2 checked	XDS 162kw and above

Assuming you're also doing the changes for 288mm to 312mm then change byte 4 and 17...
From: 04FA8AA12425296E0380060941C82920512494C0608294F3F4205078C009
To: 04FA8AA13425296E0380060941C82920512C94C0608294F7F4205078C009

And if you also want the starting torque byte changed to reflect the torque of 2.0 gasser that's byte 25...
From: 04FA8AA12425296E0380060941C82920512494C0608294F3F4205078C009
To: 04FA8AA13425296E0380060941C82920512C94C0608294F7F4405078C009

May be worth doing one set of changes at a time. If it doesn't "like" a change it's just going to kick back a "request out of range" error but you won't know which of the changes it didn't like. No security access needed to change ABS coding.

 

[golfdave]

You have to enter the coding string manually.

So for the change to byte 23 you would change byte 23...
From: 04FA8AA12425296E0380060941C82920512494C0608294F3F4205078C009
To: 04FA8AA12425296E0380060941C82920512494C0608294F7F4205078C009

Assuming you're also doing the changes for 288mm to 312mm then change byte 4 and 17...
From: 04FA8AA12425296E0380060941C82920512494C0608294F3F4205078C009
To: 04FA8AA13425296E0380060941C82920512C94C0608294F7F4205078C009

And if you also want the starting torque byte changed to reflect the torque of 2.0 gasser that's byte 25...
From: 04FA8AA12425296E0380060941C82920512494C0608294F3F4205078C009
To: 04FA8AA13425296E0380060941C82920512C94C0608294F7F4405078C009

May be worth doing one set of changes at a time. If it doesn't "like" a change it's just going to kick back a "request out of range" error but you won't know which of the changes it didn't like. No security access needed to change ABS coding.

Many thanks!..

I did the Byte4=34 & Byte17=2C at the same time & it accepted the coding...ignition off.....then on & checked for fault codes & the coding..all ok....

I had wondered about Byte25....

If it was tick boxes, I pressure my car would have Bit1 & Bit5 checked....is that what the "20" is??


All this translating from one language & then into binary!....I just don't get why VCDS doesn't have the tick boxes for this module!

 

[Cuzoe]

@golfdave I'm not sure... I suspect that since there is no published data it's probably best to not allow an easy way to mess things up.

HEX 20 = Binary 0010 0000, so bit 5 checked
HEX 40 = Binary 0100 0000, so bit 6 checked

Bit 5 and 6 checked would be 0110 0000, HEX 60

I've spent years converting F-16 Flight Control (and other) System faults from HEX (as they are reported) to binary in order to isolate problems so I tend to do these conversions in my head. But the easiest way for me to look at is the the HEX values in our modules are really two single HEX values, each represented by a 4 bit binary, which is why I split them up above. Stolen table has the conversions though...

 

[golfdave]

@golfdave I'm not sure... I suspect that since there is no published data it's probably best to not allow an easy way to mess things up.

HEX 20 = Binary 0010 0000, so bit 5 checked
HEX 40 = Binary 0100 0000, so bit 6 checked

Bit 5 and 6 checked would be 0110 0000, HEX 60

I've spent years converting F-16 Flight Control (and other) System faults from HEX (as they are reported) to binary in order to isolate problems so I tend to do these conversions in my head. But the easiest way for me to look at is the the HEX values in our modules are really two single HEX values, each represented by a 4 bit binary, which is why I split them up above. Stolen table has the conversions though...

View attachment 294540

Thanks again..will have bash with VCDS tomorrow...& take the car for as short drive around the block to make 100% certain no faults are thrown up....!!!

 

[golfdave]

And if you also want the starting torque byte changed to reflect the torque of 2.0 gasser that's byte 25...
From: 04FA8AA12425296E0380060941C82920512494C0608294F3F4205078C009
To: 04FA8AA13425296E0380060941C82920512C94C0608294F7F4405078C009

I did Byte25 ok...then Byte23 from F3 to F5 (not F7)....so 1111 0101......I have auto hold function (bit0 checked...)

I figured out what the language is..Binary is basically the bit boxes backwards...so far right is bit0...far left is bit7....

I got this when I clicked on the show libcode file section in VCDS, which temporarily showed the old tick boxes & I figured it out!!!

& the module accepted the coding..will take for short drive later tonight!

 

[Cuzoe]

@golfdave My mistake with suggesting F7, which would be 162kw and above.

F5, as you have entered is correct... I edited my post above with a note referring to your post, so no one gets confused.

And yes, binary is 0s and 1s (unchecked and checked), read from right to left, starting at bit 0.

 

[tigeo]

@golfdave My mistake with suggesting F7, which would be 162kw and above.

F5, as you have entered is correct... I edited my post above with a note referring to your post, so no one gets confused.

And yes, binary is 0s and 1s (unchecked and checked), read from right to left, starting at bit 0.

Mind blown....learn something every day.

 

[golfdave]

@golfdave My mistake with suggesting F7, which would be 162kw and above.

F5, as you have entered is correct... I edited my post above with a note referring to your post, so no one gets confused.

And yes, binary is 0s and 1s (unchecked and checked), read from right to left, starting at bit 0.

Many thanks for your help especially that conversion table!

Mind blown....learn something every day.

Same here..it was weird I couldn't figure it out...now I get it.....& will going back looking at all the coding etc & that I did to the car..& some attempts I might re-try again as I understand the coding at a base level...

Basically when you look at the VCDS tick boxes they are as stated 0=unchecked or 1=checked. (0 or 1 for Binary)

However the order originally got me confused....so you read the tick boxes as a vertical list going down the page from Bit0 to Bit7.....

Binary however is a horizontal list, read left to right as Bit7 to Bit0.....

For Hex then separate the first 4 (Bit7 to Bit4) & read that on the conversion table...then do the same for the other 4 (Bit3 to Bit0)

When it states "mirror of Byte"...if the original was 0011 0100......then for the mirror you write=0010 1100