Backup file (how-to-use)

What is a backup file?

The backup file contains all the memories of the MCU.
The extension used is .zip or .bak. It can be decompressed with any decompression software that supports .zip format (e.g., Winzip, 7zip)

This file is automatically saved during boot or bench read in the "Autotuner ECU backups" folder. This folder can be accessed by opening the Windows File Explorer and pasting the following address:

%userprofile%\documents\Autotuner ECU backups\

( The Windows File Explorer can be opened by using the keyboard shortcut "Windows Key + E" )

Maps are usually found in iflash0 or iflash1. These are variable pieces of data that occupy only a part of the memory, the rest is code to make the computer working.

As part of a boot or bench tricore reading we find:
iflash 0
iflash 1
dflash 0
dflash 1
(eflash) if the MCU has an external flash memory


In the context of an OBD reading, no backup file is saved.

The backup file has two functions:

- Return a vehicle to its original state
To do this, the user has the option to directly write the backup file within the ECU.
The slave user has the option to write the backup file on his own initiative without intervention from his master.

- Edit data not related to engine mapping
Thanks to backup file, you can modify the data located outside the maps area.
Any modification made to a file contained in the backup file causes the modification of its checksum.
Therefore, if the data has been modified, the user must systematically correct the checksum before writing one of the files from the backup.

Backup files extensions

Complete name : DATE-TIME-SERIALNUMBER-BRAND-MODEL-YEAR-ECU-METHOD-backup

Master = .zip

ex : 20190220-100134-20190000-BMW-X3-2011-MSD80-Bench-backup .zip

Slave = .bak

ex : 20190220-100134-20190000-BMW-X3-2011-MSD80-Bench-backup .bak

How-to-use full backup file ?

Find the backup file in the "Autotuner ECU backups" folder
Extract the contents of the backup file using software that supports .zip format
Modify the required part of the backup (iflash 0, iflash 1, dflash 0 and dflash 1)
Perform the checksum correction individually on each part that has been modified
Create a .zip archive that includes all parts of the backup (iflash 0, iflash 1, dflash 0 and dflash 1)
Write the backup file in the ECU


Do not create a .zip archive of a folder that includes the different parts of the backup file. The different parts must be compressed together in a .zip format. When extracted, files must be located directly at the root of the directory.

Updated on: 22/02/2019