Originally Posted by Chevota

Not sure how long to disconnect the battery for. I think a few minutes should be plenty but I've read some cars need hours or over night. I guess I'd do overnight if it's not a big deal, otherwise do whatever you can.
Apparently the time issue is some modules can hold voltage in a cap(s) for xx time so they're not reset until drained down far enough. Which, or if any, MB modules do that I can't say.

Then afterwards everything may work fine, or you may have lost some things. For me I usually lose the memory position for the left rear window, so when I close the door it's ~1/4" or so open. I have Coupe so they open when you open that much when you open the door, then roll up when you close it. So I think that function is affected and it doesn't know where closed is? That 1/4" is just the usual amount, it varies and one time it opened about 3".
The reset procedure is opening the window while holding the button down and keep holding for 5 sec after it stops, then repeat on the up stroke. This is claimed to tell the module; "hey stupid, this is where fully open and closed is" since it can't figure it out on its own. I've found that on mine it doesn't need 5 sec, 2 sec works, and I only need to do the up stroke. It doesn't always work either so I do the reset and as soon as I let off the button it opens again. I may do it five or so times and nothing, and give up, then the next day I do it once and it works. Go figure.
Another is I lose the folding mirrors, so I go into the menu and turn that option Off, close out of the menu, turn the ignition Off, then go back in and turn it back On and it usually works. The one time it did not work I tried turning it Off, ignition Off, then I closed the door and locked it. Then got back in turned it back On and they worked. Not sure if the whole locking thing made a difference, but fyi. I don't recall any other issues but my last car I'd lose my radio presets and I think seat memory?

PeterUbers: I see you have an E40 tune. I've been able to go up to 50% Ethanol (mixing E85 and 91) on my car so far and wondered if you're aware of any Ethanol related issues, like the pumps or lines etc being damaged? I hear stories but I wonder if these cars are immune or not? I do it because I get a lot of spark retard on 91 octane, which is all that's available. At ~30% Eth that goes away, and 50% I can add 1.5 deg timing at full load. All stock except the ECU tweaking I do to get it to cooperate on that much Ethanol.
Mine is a '16 E550 Coupe 2wd

Originally Posted by Chevota

I have an OE 100 Oct tune but I can't quite use that, it's .75 degrees too much timing. I know how that sounds but it would cause the ECU to pull timing and it doesn't just pull the .75, it's usually 3 on up to 6 degrees. Not sure if you look, but if it's pulling timing then it ends up being worse than the oem timing. Not just the timing either, but at some point the ECU will pull power too. I learned that with 91 octane, which is what the car is supposed to use but it pings/retards a lot! If I retard the timing to work on 91 (3 deg at full load), I net a good chunk more power. With the 50% Eth I can only go 1.5 deg over oem, but that's 4.5 over 91. So I rekon the car really wants 94-95 Oct and I'm currently ~96 or so? Just a guesstimate.

I'd love a TCU tune, just not willing to pull my plate out, send it off and wait a week. Plus the risk of damage or loss in shipping. Nor looking fwd to paying $1800.
Plus, with my crappy luck, I'd go through all that and the next month there will be a way to do it myself, which is what I really want to do anyway.
I get the usual throttle closing in 1st, and of course less so in 2nd and so on, but I also seem to have enough power that it doesn't matter? I mean I can spin them until it shifts into 3rd, so despite closing the throttle I still have more than I can use. I dunno, I guess I won't really know until I do it, and I'm sure 3rd gear would be better.
So with this EDOK tune thing you have wait until they roll into town? Man, he's probably gotta line of people begging to give him $. I also wonder how an OBD port tune works compared to a bench tune? I wonder if it can really access everything or just kinda half-***? I saw another OBD version and it looked half-*** to me. I actually have one, a lame one, and all it does it lock the oem settings to the most aggressive. Meaning those stupid "adjusts to your driving style" settings, which are those same ones you reset doing the throttle reset talked about earlier.
Sprint Booster so one of those throttle thingies right? I actually softened my throttle off idle because it was too sensitive, then it's about oem at the half way point, then it ramps up slightly quicker above that. It's infinitely adjustable to whatever I want. I could make it so the pedal doesn't do anything at all, or goes from idle to just a kiss of the pedal it's full throttle, or could reverse it so floored is idle and not touching it is full throttle. Never tried those btw, but it's doable.

Originally Posted by pierrejoliat

Hopefully you just closed the hood too softly, open hood and close it with more force, should go away as it's the hood open sensor.

Originally Posted by Aussie_E350_Wag

Ok I have had both batteries disconnected overnight,
put it back together this morning and went for a drive, the gearbox was silky smooth and all seemed good. Stopped at a roundabout and took off using a bit more throttle and the sudden power loss was still happening, I'll swap throttle peddles from my good car and see if that's the issue

Cheers!!

Since power down of the car it's now got this error on the dash??

​​​​​​Any ideas why or how to clear it?

Originally Posted by Aussie_E350_Wag

***UPDATE***

After throttle peddle swap nothing changed, powered off car with both batteries off, reconnected and car much better than before, it still has the issue but its less severe and less frequent, I am getting Benzninja to remote into the car to fix a few things and we'll see if he can see anything in the logs about the throttle cutting out issue.