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      03-05-2020, 12:44 PM   #1
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Drexler differential upgrade issues!

I am fully aware this is the F87 M2 forum but the same would apply and I'm not having any luck with M4 owners.

So, Iím Currently working on a friends 2018 F82 M4 CS and the differential has been upgraded to a Drexler LSD.

Hereís where the fun begins... It no longer utilises or uses the servo motor which was apart of the original differential, now with a blanking plate installed which means that obviously there is no where for it to go.

Anyway... this means the car needs specific coding or a flash for it to work without error in the GHAS or DSC. If I disconnect the GHAS the car should drive with minimal issue and I only get a DSC/ABS Error for communication with GHAS as a fault code.

GHAS connected and the car has fault codes for servo motor errors and communication, which is then also in the DSC.

However, the car in drive mode and reverse will barely move a couple of inches under its own power, even with the servo plugged in. (DCT)

An honestly is sounds like the differential build has been messed up because the right rear wheel spins off the floor on a lift but the left one doesnít at all, along with a grinding noise from the right as if the diff isnít built properly.

Does anyone know if this is normal or am I doing something fundamentally wrong here because as far as I'm aware, the car should still drive with the GHAS disconnected?

Does anyone know the coding/flash data required for this and can they point me in the right direction please?
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      03-06-2020, 08:12 AM   #2
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Quote:
Originally Posted by Marvins View Post
I am fully aware this is the F87 M2 forum but the same would apply and I'm not having any luck with M4 owners.

So, Iím Currently working on a friends 2018 F82 M4 CS and the differential has been upgraded to a Drexler LSD.

Hereís where the fun begins... It no longer utilises or uses the servo motor which was apart of the original differential, now with a blanking plate installed which means that obviously there is no where for it to go.

Anyway... this means the car needs specific coding or a flash for it to work without error in the GHAS or DSC. If I disconnect the GHAS the car should drive with minimal issue and I only get a DSC/ABS Error for communication with GHAS as a fault code.

GHAS connected and the car has fault codes for servo motor errors and communication, which is then also in the DSC.

However, the car in drive mode and reverse will barely move a couple of inches under its own power, even with the servo plugged in. (DCT)

An honestly is sounds like the differential build has been messed up because the right rear wheel spins off the floor on a lift but the left one doesnít at all, along with a grinding noise from the right as if the diff isnít built properly.

Does anyone know if this is normal or am I doing something fundamentally wrong here because as far as I'm aware, the car should still drive with the GHAS disconnected?

Does anyone know the coding/flash data required for this and can they point me in the right direction please?
Sorry for the obvious question, but has the manufacturer or supplier been able to give any guidance?
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      03-06-2020, 10:26 AM   #3
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Originally Posted by Got f1? View Post
Sorry for the obvious question, but has the manufacturer or supplier been able to give any guidance?
I don't see f-series m2/m3/m4 listed as supported cars on their site.
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      03-06-2020, 02:12 PM   #4
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Quote:
Originally Posted by Got f1? View Post
Sorry for the obvious question, but has the manufacturer or supplier been able to give any guidance?
I don't see f-series m2/m3/m4 listed as supported cars on their site.
They do have support, also, the M2 CS Racing uses a Drexler (non-active) LSD complete pumpkin..


https://shop.drexler-motorsport.com/...fferential-bmw

Picture of a F-Series M235i Drexler unit:
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      03-06-2020, 06:09 PM   #5
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Throwing it out there if the diff is fully mechanical then the wheels should be able to be rotated on the lift or the car be pushed on the ground in neutral.

If you cannot push in neutral then disconnect the drive shaft as now it is isolated to the rear diff and push the car. If it doesn't move I would assume mechanical issue?
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      03-06-2020, 06:25 PM   #6
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Originally Posted by Marvins View Post


Does anyone know the coding/flash data required for this and can they point me in the right direction please?

You have to VO code out the active diff (GHAS), so the vehicle's logic would know there was a change. Only software like Esys can accomplish this.

If you don't, the vehicle would go into a sort of limp-mode because it assumes the required equipment is missing or defective. VO coding removes it from the factory order, so the computer doesn't look for it.
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      03-09-2020, 01:55 PM   #7
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I did speak to Drexler Germany and it was like pulling teeth at first.
Anyway, they confirmed the obvious that the car should still drive other than the issues with it throwing errors on the iDrive and Kombi, which is to be expected.

I had to double check this only because said friend was adamant that the cars built with these differentials do not move until programmed, yet logic with a mechanical differential would most definitely dictate otherwise.

With the propshaft spinning under load yet the drive shafts were static regardless of RPM, it clearly suggests that the issue is with the differential.

Quote:
Originally Posted by Poochie View Post
You have to VO code out the active diff (GHAS), so the vehicle's logic would know there was a change. Only software like Esys can accomplish this.

If you don't, the vehicle would go into a sort of limp-mode because it assumes the required equipment is missing or defective. VO coding removes it from the factory order, so the computer doesn't look for it.
Yeah, I thought this may be the case. Thank you for pointing me in the right direction!

Since today, the owner has conceded that the differential is at fault, only after I'd made half a dozen calls and emails to prove him wrong.

Thank you all for posting replies and this concludes the part of the issue with the differential. I will post again to conclude on the the coding side for anyone that would like to DIY in future.

Edit:After looking into the vehicles VO, nothing is in there for the differential. I'm wondering if this is a DSC coding due to that being the only module to throw a tantrum when the GHAS is unplugged.

I.e GHAS communication error in the DSC.

Last edited by Marvins; 03-09-2020 at 02:42 PM..
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      03-10-2020, 01:29 AM   #8
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Not sure what's the VO code ID for GHAS but these threads below gives a rough blueprint on a possible procedure.

If you can somehow figure out how the M2 CS Racing or M4 DTM is coded, you can copy and paste that same parameters to eliminate the eLSD and get the DSC to work in harmony without an error, since factory, those vehicles doesn't utilize an active LSD but a standard mechanical Drexler unit.

Good luck


https://f80.bimmerpost.com/forums/sh....php?t=1352309


Is it possible to code GTS Diff or EPS on a MT? https://f80.bimmerpost.com/forums/sh....php?t=1462467
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      03-10-2020, 04:20 PM   #9
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Out of curiosity, what has him switching to the mechanical diff?

Also - what mechanically is wrong with the unit he provided? Have you opened it yet?
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      03-11-2020, 12:26 PM   #10
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Quote:
Originally Posted by Proctor750 View Post
Out of curiosity, what has him switching to the mechanical diff?

Also - what mechanically is wrong with the unit he provided? Have you opened it yet?
After closer inspection it was noted a fitting error of the drivers side driveshaft was not completely in its home position. Which then naturally refused to let the car drive under its own power. All is sorted now though.

Poochie Thank you!
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      03-11-2020, 03:22 PM   #11
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So I have gathered the GTS coding for DSC, GHAS & EPS but I just wondered if anyone could confirm (IF) the ICM coding for me please as this is the only reference to the differential in there...

screen shot attached.

The comment aboved data directly translates to the following...

Comment = 6yw130627: F31Alpina D3 with HAS
yw130514: Enable Alpina D3 with HAS
yw120129: N57D30 at F30
yw120822: new unregulated_has_built (03)
re110606: F80,82,83 have true (according to Sedlmayr)

From my understanding there, it shows the coding should be unregulated as standard for the F8X?

If i am wrong, this is wrong or i am completely in the wrong place, can someone tell me and explain why please?
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      03-12-2020, 11:17 AM   #12
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Quote:
Originally Posted by Poochie View Post


Is it possible to code GTS Diff or EPS on a MT? https://f80.bimmerpost.com/forums/sh....php?t=1462467
Assuming you drive a manual trans with all nannies off - what difference would the GTS diff coding make? Does it change the lockup ratio with different criteria?
Could you theoretically code the diff to a static lockup if desired as well (or have it tied to a settings knob/potentiometer)?
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      03-12-2020, 11:32 AM   #13
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Quote:
Originally Posted by Proctor750 View Post
Quote:
Originally Posted by Poochie View Post


Is it possible to code GTS Diff or EPS on a MT? https://f80.bimmerpost.com/forums/sh....php?t=1462467
Assuming you drive a manual trans with all nannies off - what difference would the GTS diff coding make? Does it change the lockup ratio with different criteria?
Could you theoretically code the diff to a static lockup if desired as well (or have it tied to a settings knob/potentiometer)?
Well, the lockup for the Drexler diff is 30% on acceleration and 9% on deceleration, without input from the vehicle's logic. It's sort of a "dumb" diff, if that makes sense.

The Active M Differential is capable of 100% lockup but it's controlled by the vehicle's computer and allotted by need only, which can sometimes be jarring in racing situations, as the ECU seeks the best lock-up, for the street.

What you gain by a Drexler non-active diff is predictability and also it doesn't generate as much heat as the Active M Diff, which is better fitting for continuous, high-endurance racing situations.

Since the Active M diff works in tandem with the DSC, decoding it would send the system in a fail-safe, limp mode.
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      03-29-2020, 04:20 PM   #14
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Quote:
Originally Posted by Poochie View Post
Well, the lockup for the Drexler diff is 30% on acceleration and 9% on deceleration, without input from the vehicle's logic. It's sort of a "dumb" diff, if that makes sense.

The Active M Differential is capable of 100% lockup but it's controlled by the vehicle's computer and allotted by need only, which can sometimes be jarring in racing situations, as the ECU seeks the best lock-up, for the street.

What you gain by a Drexler non-active diff is predictability and also it doesn't generate as much heat as the Active M Diff, which is better fitting for continuous, high-endurance racing situations.

Since the Active M diff works in tandem with the DSC, decoding it would send the system in a fail-safe, limp mode.
jarringly, the car drives absolutely fine with the GHAS disconnected.

Unfortunately I still have the issue with programming the DSC to stop monitoring the GHAS as it only shows a communication error and a DSC error on the KOMBI & iDrive display.

I have looked at FDL coding but there is very little related to the GHAS in the DSC and ICM, it is also on communication with the ZGM but i highly doubt trying to program or FDL code the gateway will stop the DSC searching for the GHAS.

I have looked at FDL coding and VO removal, but there are no VO codes relating to the GHAS in the vehicle.

However, I am currently searching for a way to remove/delete modules in the SVT's and potentially look for a way to flash the DSC if required when the software is removed.

The search goes on and I will keep you all updated.

Edit: Unfortunately the M4 GTS FDL coding doesn't work either

Last edited by Marvins; 03-29-2020 at 04:25 PM..
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      03-29-2020, 05:19 PM   #15
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Quote:
Originally Posted by Poochie View Post
Not sure what's the VO code ID for GHAS but these threads below gives a rough blueprint on a possible procedure.

If you can somehow figure out how the M2 CS Racing or M4 GTS is coded, you can copy and paste that same parameters to eliminate the eLSD and get the DSC to work in harmony without an error, since factory, those vehicles doesn't utilize an active LSD but a standard mechanical Drexler unit.

Good luck


https://f80.bimmerpost.com/forums/sh....php?t=1352309


Is it possible to code GTS Diff or EPS on a MT? https://f80.bimmerpost.com/forums/sh....php?t=1462467
It's not going to be VO coding because having or not having the M diff was never an option during ordering, so it will likely be found in FDL coding.

This level of coding is beyond what I normally do, so maybe the guys over on the dedicated coding forums will know the answer to this.


But this diff option is pretty cool, it should solve alot of the m diff over heating issues when pushing more power than factory.
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      03-30-2020, 12:11 AM   #16
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Quote:
Originally Posted by F87source View Post
Quote:
Originally Posted by Poochie View Post
Not sure what's the VO code ID for GHAS but these threads below gives a rough blueprint on a possible procedure.

If you can somehow figure out how the M2 CS Racing or M4 GTS is coded, you can copy and paste that same parameters to eliminate the eLSD and get the DSC to work in harmony without an error, since factory, those vehicles doesn't utilize an active LSD but a standard mechanical Drexler unit.

Good luck


https://f80.bimmerpost.com/forums/sh....php?t=1352309


Is it possible to code GTS Diff or EPS on a MT? https://f80.bimmerpost.com/forums/sh....php?t=1462467
It's not going to be VO coding because having or not having the M diff was never an option during ordering, so it will likely be found in FDL coding.

This level of coding is beyond what I normally do, so maybe the guys over on the dedicated coding forums will know the answer to this.


But this diff option is pretty cool, it should solve alot of the m diff over heating issues when pushing more power than factory.
I found S247A that might be the VO code for the GHAS.

I know the active diff is not a selectable option but almost everything has a corresponding code, I'm guessing that done for internal build confirmation or parts replacement.

https://www.e90post.com/forums/showthread.php?t=717103
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      03-30-2020, 12:14 AM   #17
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Quote:
Originally Posted by Poochie View Post
I found S247A that might be the VO code for the GHAS.

I know the active diff is not a selectable option but almost everything has a corresponding code, I'm guessing that done for internal build confirmation or parts replacement.

https://www.e90post.com/forums/showthread.php?t=717103
Interesting, but just because it has a designation code doesn't mean the FA menu can have it removed right? I'm not too sure, maybe it can. But what I thought is that you can access the differential settings in the SVT tree and FDL code the diff so the car just ignores it. Maybe it's not that easy.
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      03-30-2020, 12:18 AM   #18
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Quote:
Originally Posted by Marvins View Post
Quote:
Originally Posted by Poochie View Post
Well, the lockup for the Drexler diff is 30% on acceleration and 9% on deceleration, without input from the vehicle's logic. It's sort of a "dumb" diff, if that makes sense.

The Active M Differential is capable of 100% lockup but it's controlled by the vehicle's computer and allotted by need only, which can sometimes be jarring in racing situations, as the ECU seeks the best lock-up, for the street.

What you gain by a Drexler non-active diff is predictability and also it doesn't generate as much heat as the Active M Diff, which is better fitting for continuous, high-endurance racing situations.

Since the Active M diff works in tandem with the DSC, decoding it would send the system in a fail-safe, limp mode.
jarringly, the car drives absolutely fine with the GHAS disconnected.

Unfortunately I still have the issue with programming the DSC to stop monitoring the GHAS as it only shows a communication error and a DSC error on the KOMBI & iDrive display.

I have looked at FDL coding but there is very little related to the GHAS in the DSC and ICM, it is also on communication with the ZGM but i highly doubt trying to program or FDL code the gateway will stop the DSC searching for the GHAS.

I have looked at FDL coding and VO removal, but there are no VO codes relating to the GHAS in the vehicle.

However, I am currently searching for a way to remove/delete modules in the SVT's and potentially look for a way to flash the DSC if required when the software is removed.

The search goes on and I will keep you all updated.

Edit: Unfortunately the M4 GTS FDL coding doesn't work either
Sorry you're still having an issue, the active LSD is spirt of an M car's handing and is part of integrated vehicle dynamics, so it's not surprising it's this hard to eliminate, it's almost like changing a major ingredient in a cake, if you know what I mean.

Just as how when a vehicle comes with Adaptive Suspension, it's a nightmare to eliminate for coilovers because they're tied to the steering and DSC software logic.

I listed a coding directory in my previous post that might identify the GHAS VO map, check it out, good luck and keep us updated.
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      03-30-2020, 12:24 AM   #19
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Quote:
Originally Posted by F87source View Post
Quote:
Originally Posted by Poochie View Post
I found S247A that might be the VO code for the GHAS.

I know the active diff is not a selectable option but almost everything has a corresponding code, I'm guessing that done for internal build confirmation or parts replacement.

https://www.e90post.com/forums/showthread.php?t=717103
Interesting, but just because it has a designation code doesn't mean the FA menu can have it removed right? I'm not too sure, maybe it can. But what I thought is that you can access the differential settings in the SVT tree and FDL code the diff so the car just ignores it. Maybe it's not that easy.
To answer your question, I'm not to sure, I would be guessing, unless I had a change to dig into it myself but that should be the corresponding directory code for the GHAS.

The brand new M2 CS Racing doesn't use an M Active Diff but a regular locking LSD, à la that of the M Performance Drexler unit, offered in the standard BMWs.

I'm assuming if he finds a new PSdZData file for the CS Racing, he might be able to use that to remove the electronic diff, in one quick swoop via VO.

Sorry, my expertise end there but a profession coded might be able to help.
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      03-30-2020, 12:52 AM   #20
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Quote:
Originally Posted by Poochie View Post
To answer your question, I'm not to sure, I would be guessing, unless I had a change to dig into it myself but that should be the corresponding directory code for the GHAS.

The brand new M2 CS Racing doesn't use an M Active Diff but a regular locking LSD, ŗ la that of the M Performance Drexler unit, offered in the standard BMWs.

I'm assuming if he finds a new PSdZData file for the CS Racing, he might be able to use that to remove the electronic diff, in one quick swoop via VO.

Sorry, my expertise end there but a profession coded might be able to help.
Yeah if we had access to the m2 C's racing PsdZdata files it would be easier to find out the differences.

Yeah I'm not professional coder either, so I'm just spitting out some ideas, so take them with a grain of salt when it comes to this stuff.
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      04-02-2020, 05:38 PM   #21
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I have exhausted all avenues with current software up to now.

S247A wasn't part of the FA either. Not much seems to be known about this issue and anyone ive contacted about it either flat out claims it something they cant do or that they can do it and they will do it remotely... but never message me back when i ask to book it in

Does anyone know if the 4.22.31 PSdZdata contains the M2 CS or GTS codings?
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      04-03-2020, 06:57 PM   #22
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Quote:
Originally Posted by Poochie View Post
To answer your question, I'm not to sure, I would be guessing, unless I had a change to dig into it myself but that should be the corresponding directory code for the GHAS.

The brand new M2 CS Racing doesn't use an M Active Diff but a regular locking LSD, ŗ la that of the M Performance Drexler unit, offered in the standard BMWs.

I'm assuming if he finds a new PSdZData file for the CS Racing, he might be able to use that to remove the electronic diff, in one quick swoop via VO.

Sorry, my expertise end there but a profession coded might be able to help.
The latest data I could get my hands on is the 4.22.31 Lite for now with the full 4.22.31 Psdzdata still in download.

Unfortunately I can not see many differences in the right places it would need to be.

However, there is parameters to code in which I haven't tried, one because i can not find any data on it and two, because multiple codes state "Unknown."

There is F80 M3 CRT for the carbon packaged etc in there for a codable variant in the DSC, yet i can not find any information relating to this model, an then there is the 5 UNKNOWN parameter codes.

I may pop in there tomorrow and see how i get on with these parameters and update from there unless anyone can give a reason why I shouldn't try and code these model variants?

(See attached screenshot for details on variants in the DSC.)

If anyone would like to take a second look at the FA, SVT & CAFD files and see if I'm overlooking anything, let me know and i will email them to you.
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