Audi A8 2004 4.0 tdi

[teerak2uk]

Just read one of these and left with 2 files is this normal?

[ominimicu]

Yes these car ahve double edc16 ECU a slave and master. U have to reprogram both of them or it wont work

[teerak2uk]

Yes these car ahve double edc16 ECU a slave and master. U have to reprogram both of them or it wont work

When writing back does it make a difference which is wrote back first

[ominimicu]

NO absolutely not, u shoudl actually get same file from both ecus, so just write same mod on both.
sometimes i even BDM them so makes no diference with is first

[teerak2uk]

How do you know when writing master that you are writing to correct part of double ecu or just write master files then slave file and it automatically goes to correct part (obd writing)

[J_amb_o]

Most tools you can select which ECU you are writing to. The flash is the same, but the EEPROM coding is not.

[ominimicu]

If u read both flashes OBD OR BDM u can use any hex editor and compare and u gt IDENTICAL files.
so how does it matter which goes where?
i did so many of thesee as long as both ecus have same flash info it will be fine