Hi guys,
In need of some advice.

My car has a stock 4B0907551S, I've sourced a stock 4Z7907551D and removed the immobilizer.
When I've used this new ECU (551D) the car started beeping and the (!) symbol was flashing in the dash together with ABS and ESP warnings. (And ABS module error P1849 - 35 - 00 )
I've assumed it was the ABS module misbehaving and tried to code it using VCDS (following this procedure http://wiki.ross-tech.com/wiki/index.php/Audi_A4_(8D)_Brake_Electronics_(Bosch_5.3_ABS/EDS/ASR/ESP) )
I was able to code it but when I got to the adaptation part I got an error saying that I needed the registered version (I was using the light version) .
I refitted the original ECU (551S) assuming that everything would be fine but the issue remains.

(please check video : https://www.youtube.com/watch?v=PPRmnx4pDfE )

My guess is that now the ABS module is not recognizing any of the ECU's and I need to use the full version of VCDS to code it. But I wanted the validation before investing 200$.



29/05/2020 - Edited title for visibility.
From:ABS / ESP problems
To:P1841 - 35 - 00 Engine Control Module / Transmission Control Module Incompatible

I was not aware of vcds clones. I'll search for it.


So, what should I do? I had searched s4wiki and the solution appeared to be to code the abs.
https://s4wiki.com/wiki/Anti-lock_braking_system

Solution is to code new ECU to same as old was

Share your old / new EEPROMS and ROMs and someone can point you in the right direction.

OK, thanks for the help.

In trans what DTC you have?

Any insights guys?

Well, because I'm a noob. And since different programs exist for different purposes I assumed that writing the original soft would only write into a specific part of the memory instead of making the ecus an exact copy.
(Also I previously compared both files with tuner pro and no differences were found, probably because they are not defined properly)

Regarding the coding I'm also confused because  both are coded 00001 regarding trans coding.

On top of that I was worried that some hw difference could exist.

But thanks for the input I will test with the original soft on this ECU and pick it from there. However I'm afraid this will happen again once I flash a more defined file into the ecu.