ECM requires a software update to enable tuning ?

Hi, I tried to read my own car tuning (2015 W222 S550 4.7 V8) just to take a look at what parameters are available and to get familiar with it, so I connected my MPVI2+ and started reading and selected the hardware to: MED 177 and MED 17.7.1 and (i couldn't read what is there actually), anyway, my car as I read from the internet should be MED 17.7.1 "not sure"

However, after selecting the hardware and pressing "Read" a pop-up message comes up asking me to update the ECM in order to enable tuning. I freaked out as I didn't want to do any adjustment all I want is to read for now.

Attachment 118072

so I stopped there and started to search online but couldn't find any answers except for some whose the update failed and ruined the ECM and the car wouldn't start and the solution was to look for crashed files...

anyway, is it safe to perform the update and has anybody performed it ??
is there any precaution to be made before doing it?

Yes, it requires an update/patch to be able to communicate with that ECU. I think it's because the ECU has some other chip/protocol on it that is different. I forget the name but it is an obstacle. I had to do it too and I read it can brick on you during this process but I don't know the details so just rumor. I also don't know if it's a real bricking, as in you're screwed, or you just need reload the patch again.
I'd read the sticky posts on it and maybe search a bit, but I didn't bother because I wanted a spare ECU anyway. I found a spare on ebay for $200, cloned it to mine, then put the patch on the clone.
Later, I patched my oem ECU and it scared me because it got stuck. It loaded, then stuck on "verifying". I let it run for a while but the ignition On drains ~9amps so after ~20min of waiting I killed it. I expected to have to load the patch again, or maybe this was the bricking I heard about, but no, it took the patch and was fine.

So I can't say don't be paranoid about it, because I was. I also believe that even if you don't buy a spare ECU, I think you should back up yours just in case this or anything at all happens. It costs ~$80 for the hardware to do that and it took maybe 4 days for it to arrive. Instructions were poor and NOT to be followed, but I would be happy to explain everything if you choose to do that. Once you have the backup file you can use it anytime down the road to load a junkyard ECU if you ever have the need. I saved my file twice, then saved them on several hard drives and google drive.

My spare ecu came in handy a couple times because while tuning I've made many misc mistakes and the car goes into limp mode. From there you have to have your laptop and HP dongle with you, AND connect to the HP Tuners servers and beg HP to allow you to use the software you paid for. This means using your phone as a "hot spot" and connecting your laptop to it. Well, I don't live in an area with great cell service, so twice I've given up trying and had swap to the spare ECU which lives in my trunk. Such a pita but it is what it is....

Update: The difference in these ECU's is "Tricore", which is a chip or chipset? And when backing up the ECU like I did it required an extra piece of hardware to do whatever it does or you can't even get in to copy it.

Quote:

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Originally Posted by chevota

I think you should back up yours just in case this or anything at all happens. It costs ~$80 for the hardware to do that and it took maybe 4 days for it to arrive. Instructions were poor and NOT to be followed, but I would be happy to explain everything if you choose to do that. Once you have the backup file you can use it anytime down the road to load a junkyard ECU if you ever have the need. I saved my file twice, then saved them on several hard drives and google drive.

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Thanks a lot chevota, I appreciate your quick response and offering your help.
well I think I'm going to backup the ECU as you said and then I will start updating the ECU to enable tuning.
Could you please explain more about how to make a copy of it..

Many thanks again.

I couldn't attach the file so I put it here: https://tinyurl.com/2p9ymh9d

It's my instructions plus a bunch of pictures. It's a .rar file, which is WinRAR, a zip program. If you don't use zip files you can get 7-zip, which is free and will open it. Or I can just upload a bunch of pix here, if it 'll let me.