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Technical => Reverse Engineering => Topic started by: S7Kota on September 21, 2024, 09:44:48 PM



Title: Audi ZF8 Swap and ECU/TCU incompatible fault
Post by: S7Kota on September 21, 2024, 09:44:48 PM
I know this has been done a handful of times before but it seems to be the future swap for Audi S6/S7 owners that plan on going with single turbo setups and other high horsepower builds as the original DSG DL501 cannot hold all the power these cars can make.

I currently have someone that completed his swap and everything is done on the wiring and hardware end, the issue now is getting the car to move. He has a “ECM/TCM incompatible” fault code. My best guess is that the ecu either in the coding or firmware/software is expecting to see the DSG instead of the ZF8. Now the ZF8 was a factory option but for the RS7 which is generally the same engine with some slight differences but still a 4.0T and utilizes the same MED17.1.1 ecu.

If anyone have done this before the information would be great but if not, does anyone have any ideas on how this roadblock could be overcome? The customer thought to flash an RS7 .frf but I’m afraid this might brick the ecu.

Any help or insight is greatly appreciated and hope we can figure this out to help all the future swaps!


Title: Re: Audi ZF8 Swap and ECU/TCU incompatible fault
Post by: jcsbanks on September 23, 2024, 01:31:48 AM
You can flash any version of 4.0T MED17.1.1 to any 4.0T MED17.1.1 ECU, but I just do this through OBD on the bench with immo off to check custom code runs normally, I didn't use it to run engines. People do all sorts of swaps on these, IIRC they do usually flash an RS7 ECU to run a ZF8. You can bench flash these ECUs easily if you make a mistake, best to backup everything including EEPROM before altering. You might need to change the coding in the ECU.


Title: Re: Audi ZF8 Swap and ECU/TCU incompatible fault
Post by: Audirama on September 23, 2024, 11:39:05 AM
You can flash any version of 4.0T MED17.1.1 to any 4.0T MED17.1.1 ECU, but I just do this through OBD on the bench with immo off to check custom code runs normally, I didn't use it to run engines. People do all sorts of swaps on these, IIRC they do usually flash an RS7 ECU to run a ZF8. You can bench flash these ECUs easily if you make a mistake, best to backup everything including EEPROM before altering. You might need to change the coding in the ECU.

Can this be achieved via OBD with an Rs7 bin? Well the user still retain ds1 after the swap? Those are some of the concerns we are unable to confirm. If that is doable then Odis may only be needed for tcu immo


Title: Re: Audi ZF8 Swap and ECU/TCU incompatible fault
Post by: jcsbanks on September 24, 2024, 12:32:21 AM
If you want the ECU version changed so you can flash it with the DS1, you can email a request to info@dynospectrum.com with your VIN, DS1 serial and what ECU version you want mentioning that it is the same VIN, same ECU, same vehicle. Then update the DS1 and it will flash the new version next time and everything DS1 related continues to work on the same ECU with different software. When I do this on the bench I always use immo off and keep immo off in every flash. This may or may not help with your plans, it is just replicating what I use for internal testing and various swaps have found it useful, some keeping the immobiliser and some not. There are so many combinations of engine, trans, chassis swaps we can’t support them all, we just know this way we can flash any 4.0T MED17.1.1 with immo off with any ECU version with just an ECU, DS1 and power supply on the bench and from this base info people build setups that work but the other details are on them. Many doing this find close availability of bench backup of the ECU is useful.


Title: Re: Audi ZF8 Swap and ECU/TCU incompatible fault
Post by: prj on September 24, 2024, 02:45:08 AM
If he flashes RS7 file as-is immo will not be authenticated anymore, and you can forget OBD flashing unless during unlock DS1 makes the ECU X.
In which case immo does not matter anymore anyway, as an immo off file can be flashed OBD.


Title: Re: Audi ZF8 Swap and ECU/TCU incompatible fault
Post by: jcsbanks on September 24, 2024, 04:03:33 AM
We have an immo off option that can start or stop the chain of being able to OBD flash without an immobiliser, but of course the first time (or if the chain is broken) it needs a working immobiliser or an ECU that has immo off.


Title: Re: Audi ZF8 Swap and ECU/TCU incompatible fault
Post by: prj on September 24, 2024, 06:53:20 AM
We have an immo off option that can start or stop the chain of being able to OBD flash without an immobiliser, but of course the first time (or if the chain is broken) it needs a working immobiliser or an ECU that has immo off.

I know all that, but I am just saying that so OP does not flash the car OBD with the wrong powerclass without having any recovery plan.
Because then it's ECU out time.