EcuTek Diff Files (from Multicompare tool)

Owned by Lucan Hetherington
Last updated: Sept 06, 2022
4 min read

The ROM Compare (Multicompare) tool has the ability to export selection of map changes (using the map name) to a diff sile, A diff or “.erd” file is an encrypted file that contains the map data and axis changes that the user chose to save into it. (for more info on the ROM compare tool see the article ProECU ROM Compare Tool )

This system can be used to develop an series of files that can allow you to set up base files for particular cars that have well know layouts. For example you can set up a series of Diff files for Injector Upgrades, MAF Scaling or Custom map special features you have created reducing the time needed when setting these functions up.

Creating a Diff File

To create a Diff file you use your tuned example and a stock version of the same ROM and load them into the ROM Compare (Muticompare) window. You can find the MultiCompare tool in the file drop down in ProECU.

 

Loading the tuned and stock ROM into the two windows.

Then select the map changes you wish to include in the diff file and select the copy to Diff file button

and save the file where you wish

Applying a Diff File

The diff file once created can be added to any ROM without using the ROM compare tool. To apply a Diff file all that is required is to open the ROM and prepare it with the appropriate patch etc and then apply the Diff file using the File Menu -> Apply Diff File button

select the file that you have created and open the file

It will show that the map Changes have been applied successfully

NOTE: If the maps are not able to be added a warning message will show with the map that were not successfully modified shown

separate file that can be added to a ROM

Notes and Limitations

The tool only copies data between maps. You cannot create or remove maps in the destination ROM, nor can you resize them. For example, you cannot use the tool to "add" a launch control map to ROM that doesn't have a launch control map.

The tool does not allow you to manually edit the maps.

The tool relies on map names to identify the maps you are trying to change, if these are not the same between the ROM you created the file with and the new ROM the map changes can’t be applied. Manual copying will have to be done.

Map definition changes must be the same between the old and new maps (size, axis and units) otherwise the values may not copied correctly e.g. if the map size is larger in the new ROM it will only apply the old map size to the new map leaving some values untuned.

If the target map is not correctly defined in the software it may not copy correctly. Make sure you check any ROMs to ensure your changes have applied correctly.