Existing Tune

[notmypie]

So I have A E550 that the previous owner claims that it has a renntech tune on it already. I dont know if this is true but I was wondering if the HPTuner could read it and allow me to make a backup of it just incase or will I need to get another tool to make a backup of the file?

[chevota]

In short, no, not really. You need to do what I did which is get a KESS (or KTAG) unit which is ~$80 for a knockoff and backup the file in the ECU. Then you can not only reload it, but you can load it onto another ECU from a junkyard and have a spare! This is what I did and that junkyard ECU is what I tinker with.
I wrote down all the details of buying and using the KESS, so if you want to go that route I'm happy to share. The KTAG is more well known but it's more for commercial vehicles, the KESS is virtually the exact same thing but geared more for cars so that's why I bought that instead, fyi.

Mine is a '16 E550. Should I assume yours is a turbo too? If so I'll assume it's basically the same ECU as mine; MED17.7.3, or MED17.7.something. If so, do NOT follow the instructions that come with the KESS! I have the easy how-to version.

Did the guy give you the thingy to apply the tune? Because I'd assume it could also undo the tune just as easily? That's how mine was (OE Tune) and I copied my ECU with and without the tune in it, plus the optional 100 octane tune. Then I used HP Tuners to poke around and play with them. Fyi HP can't see everything in there so it's very possible/likely you won't know what all was done. Looking at my OE Tune there is VERY little difference compared to the OEM, but again it's only what HP can see.

[outlaw_50]

- Get KESS to get a backup of your ecu first and save it in you laptop (Why get a backup? sometimes HPtuners update file get things corrupted but that happens to 10% only make sure you have good internet connection, a geniune usb cable, charged laptop and good car battery)

- Put back the ecu and now its time to read the file by HPtuners which will ask you to apply a patch using an update file

- When its done start reading the ecu and you will get the OE tune and you can compare it to a stock file from the forums here to check if its really tuned

What chevota said about things are changed in the tune that may not be shown in HPtuners is true but not the OE tunes they dont change much and you can see everything in HPtuners

[notmypie]

I have the 2014 Bi-Turbo. I?m on my phone at work so excuse the formatting.

I saw a KESS on aliexpress or should I be wary of knockoffs? Please could you share your knowledge If you could. I assume the KESS gets me a complete image of the ECU in binary?

So he said it was tuned at the dealership when he bought it but this was the guy who bought it off the guy who said that.

[chevota]

Link to my KESS info with details and pictures since it's too much to post here: https://www.transferbigfiles.com/dow...aqe82emW5xnEA2
Here's the unit I bought, which is $72.25 now: https://www.aliexpress.com/item/32356882368.html
I also bought this which is not required but it did help $24.30: https://www.aliexpress.com/item/2255800151550515.html

outlaw: I didn't know that about OE. So I paid $1k for a couple little tweaks easily done in HP Live and learn, sigh...

[outlaw_50]

Link to my KESS info with details and pictures since it's too much to post here: https://www.transferbigfiles.com/dow...aqe82emW5xnEA2
Here's the unit I bought, which is $72.25 now: https://www.aliexpress.com/item/32356882368.html
I also bought this which is not required but it did help $24.30: https://www.aliexpress.com/item/2255800151550515.html

outlaw: I didn't know that about OE. So I paid $1k for a couple little tweaks easily done in HP Live and learn, sigh...

Thats life !

[notmypie]

So I finally got the KESS in but I?m having trouble opening the Ecu. It?s a MED17.7.3

[notmypie]

So I just came back from running two short runs with just the VCM Scanner. Neat tool. Going to upload these runs. As for the KESS I could not get that to work. Chevota if you could repost your details on how to get it to work since the link expired.FirstRun.hplsecond run.hpl

First one is with basic channels. Second added torque and other channels. Now I didnt really run over 80mph but the highest torque i saw was 425ftlbs. Also Manifold Pressure was over 20Psi. Im going to look into these to see if this is right.

Once I can get the KESS working I will upload file.

[chevota]

https://tinyurl.com/4md7pktt

The ecu is no fun to open up. It's sealed with silicone as you can see in the pix, so I just started at one corner and pried with two screwdrivers as best I could, then reached in the gap with a razor and cut the silicone. Just be wary and see the pix to know how deep is safe. I had to pry hard enough that I bent the edges of the cover a bit, but I just bent them back and it looks more or less fine.

Since I posted last I added a section about making the unit bootable without having to take it apart again. Still have to take it apart once, but at least just the once. Up until I did this I was running around with no sealer, but I figured sooner or later that might bite me in the butt.

[notmypie]

Thanks I will get that tomorrow. So I saw you had issues with being limited to only 8psi boost, after going over my runs I too am not really going over 8psi boost. What did you do to solve this, In threads I saw that this is abnormal.

[chevota]

I've just been struggling just to get back to oem power levels, which I don't think I've hit yet. Not just the boost issue either, because now I avg more like 14psi yet I'm exactly as quick as you. My 8psi was not avg boost, it was peak and would drop fast to ~3. Mine now peaks ~18-19 and still drops fast to ~11-12.
Your turbos seem to hold boost just fine now but we'll see what happens when you ask more from them.

It seems clear to me there is no tune in yours. A lot of people insist 8psi is normal, but I think "normal" is because most peoples boost is low. MB claims 13, but it's also possible they stretch the truth and count boost spikes. To me there is peak that it can actually hold, then average psi through a gear. Spikes don't count except I worry about them breaking my intercooler or intake, but spikes do buy you an extra 5 or so psi if you wanted to claim that.

Getting boost up will be super easy, imo. Fine tuning I don't know about because my f'd up car is different and all my settings are high to make it work. Not sure what mine would do to a normal car but I can give it to you if you wanna see, just don't use it.
My tune has been stuck for months on torque errors. If I increase it make more power the thing will just shut down on me.


If you want, the files below should give you my scanner settings. Since we have the same car and ecu I'd imagine all the stuff will work and it's what seems important, to me anyway. Just save your two files and swap in mine and see if you like it.
You can't see all the data on playback unless you recorded with these settings, so if you play your files on this it's missing a lot.

If you don't like it just swap your files back and it'll be just like it was before.

Attachment 121415
Attachment 121416

[notmypie]

So I spent an afternoon working on a tune. Focused on removing some limits and increasing boost. Been running scans throughout the week. Had a CEL but no DTC codes at all. It went away after i did some shopping. Confused.

It will peak at 15 psi but lingers around 10-13. It feels a hell of a lot quicker. Next I want to attack the VE and Spark to pick up more power. There also is a lot to fix with the limits. There is so many different VAR tables I dont know which it uses. I changed the Normalized torque to see what it does but it just made things look weird so im going to change that back to normal this weekend.

I wanna say its running lean but fuel trims say otherwise. -10% so it looks rich OR it thinks its running rich!?

IDK I'm learning a lot and just trying to be safe. lol. I will try out your setup this weekend when i have some free time. In the mean time here is mine plus a cold start scan drive from work to home.


to comicstore.hpl run into town, hot day
night1.hpl Scan tonight from work
Tune2.hpt Tune
Tune2Normalized.hpt Tune w/Normalized torque adjustment

Also is it true we cant disable the DTC from having no cats with HPtuners?? I plan on going catless, off road of course. (drag)

[chevota]

I had that a few days ago, cel but scanner said no codes. Im going with scanner error because I always have codes. Just turning the ignition on i have codes, including overboost, go figure. At 6k my boost is ~11, i think 5k was 15? Point being the turbos and overall stock system cant give any more at those rpms in my car. Plus it varies depending on how it feels so those #'s are max.
I ping and it pulls timing with the oem spark, so i have it retarded 3deg under load and I still get some retard.
Good luck figuring out the var, so I change all of them. Theres a recent post here about Normalized, all I know is its confusing and "seems" pointless to mess with?
Ill look at your files later when i get home, thanks for sharing those!

[notmypie]

So Ive been going through my scans and I am noticing up to 3 degrees knock retard while decelerating. Knock Retard across cylinders 1,2,6,7,8. miss fire on cylinders 1 and 2. reverted to stock and still getting these reading. I'm going to assume spark plugs? Also noticed LTFT bank 2 is at -10 still even at stock

[chevota]

It's weird to see the Calculated Load go so high, mine usually stays in the 80's. I don't even know what it represents.
Your knock sensor noise is equal to or worse than mine but at that level all my cyls are at least 3deg on up to 6 retarded. Even when I richened the crap outta it and retarded the timing 3deg I still get random 3 retard. The only time that went away is when I mixed some ethanol in. I've never seen retard on decel, and I eng brake all the time.
The only time I recorded a miss is when my battery was low and when I lost a coil, never normally. So I gave up recording that. Gave up knock sensor noise too.
My trims are also very weird, but the stock is fine.
I'm curious what your Injector pulse width is.
There is a math function where you can subtract ambient to get boost. I have that to see boost both before and after the throttle. I'd imagine you'd want that one to check changes. Same with horsepower, need math to read it.

So what did the Normalizer change do? I haven't tried that one yet.
Meanwhile he's a tune I've had in it for a few days. Again, I wouldn't use it, just look-c. I have what I think is all the limits out of the way but it's just too complicated to know for sure. If some limits look extra high it's because lower was an issue. It shouldn't be, but it is.
All the weird turbo stuff is my attempt to get it work better, but I don't think it's possible via the ecu and vacuum solenoid.
E550 77x (Don't use!).hpt

[notmypie]

Like engine load? It should represent how hard the engine is expected to run. I think. Mine was in the 80s often but after adjusting TPS and a few others it went higher.

Have you upgraded spark plugs? Im going to be ordering a new set since i think its part of my issue. Although I don't know what to get, I see the NGK recommended and I saw somewhere on the mbforums a specific model be recommended. Trying to find that.
I have boost logged. I didn't know HP was math. How can I check the injector pulse width?

It changed how much torque it thought it was making. So now i see it jump into negative numbers and that's just not right. I do imagine if allows it to make a little more torque but its confusing.

Do you have any scans? Your old ones aren't available anymore.

EDIT:
Now have a list of DTC
p06AF
U0100
U0121
U0126
U0141
U0146
U0155
U0164
B210D
U0100
U0111
U0168
Lots of these are Lost Communication With. ECM, ABS, Steering Angle, Body Control, Gateway, HVAC, Battery Energy, Instrument panel, VSC

[chevota]

I record Engine Load and Eng Load SAE, which read differently. If Load is 200 and Load SAE is 230, which is the ecu using? And why are they different at all? I'd imagine a lot of people are using just one and wonder why their load is different than other peoples. Also annoying because I don't know which one is used in the charts. The data is too slow to see that, I'd need a much longer and steady run to decypher it. Like your runs you posted, which would very difficult to pull off where I live thanks to traffic. I also now have cops to deal with, who vanished during covid but came back in full force a couple months ago and seem to be trying makeup for tickets they missed out on. Undercover ones too, which is F'ing BS imo.

Calculated Load I don't understand, but my guess is it's nothing more than some math output used for some mystery reason, but just a guess. Sometimes it's down ~60 under full load which only makes it more confusing.

Injector Pulse Width is a PID in there somewhere, under fuel. We don't have many so should be easy to find.
Math is used to convert whatever data, like taking MAP minus Ambient to net intake boost. Or to average timing retard of all 8 cyls, or convert Torque and RPM to Horsepower It's fairly simple and the pix shows the gist of it. Just select a blank "User Math" and plug in what you want, which the pix shows my end result. I can send you mine if you want.
Math.jpg

I too get weird torque #'s. Negative at idle or even cruise, but also very high #'s. I've exceeded 800ftlbs and 650HP, which it isn't doing of course.

If I load the oem tune it idles fine. The trims are off but it's off by a consistent amount and doesn't do weird things. If I tune to make more power it does do weird stuff.
Here's the worst idling it did, which didn't stay pegged at the rev limiter but was just nuts: Stall.hpl
The tune in it that day: 31x Tbo (8 Jun '22).hpt
The Inj PW was high to work better with ethanol, which on this day had 28% in the tank. Basically the more ethanol the weirder idle was.

I don't believe there is any way it can tell there is ethanol in there, so I have no clue how it changes to the second fuel map. I can say that when I loaded a tune with lean primary map and rich secondary, it used the primary until I floored it, then it used the secondary. Doesn't make sense to me at all, what triggered that? If it just triggers under load then why does the primary have values for under load?


Then there's the Power Enrichment. In the attached pix that is the limit, if I change any of the cells that are 1.00 to a lower #, then it'll richen low rpm/part load. For example if I change the 80% x 4k cell to .8, then .8 is what I get cruising at <2k and <40% load. Why? Power Enrichment.jpg
Stuff like this turns what is already confusing into just about impossible to figure out.

I too have a butt-lode of DTC's. Mostly U codes but they all started after my power loss issue started and before I got HP Tuners. I forget when exactly but I get 10+ a day, up to 40 or so

[Keachman1]

Hey Chevota, could you post the link on the KESS info again and how you got it to work? The link has expired. Going to try downloading the ecu in my 2011 ML350 diesel. Thanks.

[chevota]

https://tinyurl.com/ycyd3e89

It's the new improved version. I got real tired of taking the ecu cover off, and using the BDM rack thing to hold the boot pin contact, so I modded it and eliminated all that hassle.
Now I can pull the ecu out of the car and in a couple minutes, and no hassle, I'm Xfering data. Look in the folder "External Boot Pin Mod"

[Keachman1]

Thanks for posting that again Chevota. Unfortunately, the link didn't work for me unless my pos computer is the problem.