I don't know if you can even do that with a CS 2 or 3. Only function icons, and second duration or momentary function is adjustable.

These decoders support DCC as i am able to change the volumes, or other CVs using my Multimaus DCC controller. Any idea what CV i need to change to make my F14 -> F7 function for example? Or can i somehow "unlock" my decoder using the mDecoder tool and the decoder programmer 60971 so i could reprogram it to my liking?

I have used JMRI to change function mapping on a mSD/3. Complicated, but doable.

You can reprogram newer factory decoders if the firmware is above 3.2.x.x, and Marklin has released the decoder project for that specific model. You will then need a CS3/(2?) connected to a PC, and you have to send the complete project from the PC through the CS3, to the locomotive on the programming track. This takes approx 45-50 minutes. Using a 60971 will not work. As long as you start with the specific decoder project you can change what you like, eg delete and sounds etc and change sound settings that you can not change using a cs3 alone. Usually, this works on mfx+ locomotives except for some very early ones with older decoders/firmware. On locomotives with firmware below 3.2.x.x but above 3.0.x.x, you can upgrade the firmware and make it work. but not on all. E.g it is not possible on the 39030 with firmware 3.0.0.17, because according to Mârklin the decoder is too old. Some early decoders have only a 32 MBit sound chip and you must make sure you don't exceed that limit, otherwise, the sound will be totally gibberish.
I have changed added and deleted sound files on several factory-fitted decoders without a problem. including changes to sound settings that can only be done this way. But even after a decoder is programmed in this way, it still shows up as locked if you try to use the 60971. so it's a way around the looking. not a removal of the lock.
Marklin Goppingen confirmed to me on the phone that this method of reprogramming factory-fitted decoders was not intentional, but also that they have no plan of fixing this "error". And in some cases, they provide a description to the consumer on how to do this.

Edited by user 31 October 2023 15:00:47(UTC)  | Reason: Not specified

I'm not surprised they'd tell you that Jean. They want to sell decoders to those who want more or different functions and sounds.

If the decoder is shipped without sounds programmed, and requires a decoder tool to do it, that should not void the warranty! Nor should be if a dealer installed the sound files and you wish to change it later. It is what they are designed to do.