I have reached out to a couple of folks who probably have the knowledge to make the change in software, but no takers yet.

I've got to believe the RPM speed is a variable in the code and not hard-coded. But, I'm not a software engineer. Using the RPM value as a variable may add milliseconds of processing delay over a hard-coded value, so maybe the folks at Bosch did write 3500 RPM into the code. Changing that may be impossible without having the source code.

 

We should all send nice little messages to any automotive keyboard slingers we might know.

 

Do we really think Bosch dictates how this engine runs? I don't think Mercedes hands them a long block and says "let us know when the computer is integrated and everything runs." But some on here seem to think that's how it works...

 

Of course it sees the load. That's why we all have that P06DA00 code.

 

There is zero evidence that the ECU controls the power output of the engine as a function of the oil control strategy. Rather, the oil control strategy is adapted to various scenarios. The computer doesn't wait for oil pressure to decide what power to produce or to "improve responsiveness." These changes are mechanical based on having the correct oil pressure for functions like the variable cam phasing to work as designed.

 

Yes, exactly. It makes sense to approach this whole thing conservatively but people are just getting nervous without thinking through the logic of what's happening here. Then again, I am not forcing anyone to unplug. You should, however, probably come to that conclusion after looking at all the available information.

 

Confused how Bosch entered the conversation here.

Bosch likely delivers the hardware, the programming instructions, and some skeleton software (examples). MB programs the hardware. If the program has the set points for the oil control solenoid as variables, they could be changed to another set point.

 

That's what I would expect.

 

Me, me, me! I mentioned Bosch because my understanding is that Bosch developed the programming for the ECU, though I could be mistaken. But, whether it's Bosch or not, somebody wrote the code and set 3500 RPM as the trigger point for the solenoid to change states. We just don't know if it is an adjustable parameter/variable or if it was written into the code. Sometimes coders take shortcuts so they don't have to create a look-up table for variables. Or, they hard-code a parameter to optimize code execution.

I am reaching out again to someone who would know and will post what I hear.

 

You might be right, but its safer to avoid introducing "weird" scenarios for ECU or any complex system for that matter. A bunch of stuff can be keyed off RPM (ie 3500) in ECU, including oil pressure and perhaps some safeties.

 

​​​​​​@S-Prihadi did a lot of hands-on research in this matter. And many of us have been running this "mod" for months and hundreds, if not thousands, of miles. The information presented in the 37 pages and well over 900 postings to this thread are offered up and shared for those interested in making the change. Those who are concerned, in spite of all the evidence to the contrary, about negative effects of "pulling the plug" need not do so. No one who has made this change and enjoyed the new performance benefits is twisting anyone's arm to do the same. Either do it or don't. The decision is totally yours.

 

I did the unplugging mod and happy with it, I will not fool ECU by plugging a dummy load or dummy solenoid.

 

Glad to hear that. The purpose of plugging in a real solenoid is to see if the DTC goes away. There were some folks with S63s that had CELs show up. If connecting a solenoid makes that go away for them, that might be useful information. I understand your comment about not knowing what effect adding the solenoid might have, but based on the work done here, to include research of available technical papers, it is unlikely that it will have any effect on how the engine works. Remember, Mercedes' own documentation says the purpose of the 2-stage oil pump is to reduce the viscous flow of oil in order to save fuel. There is no indication that any other controls are also activated at 3500 RPM with a working solenoid.

 

An interesting observation, before I call it a night, is that when I plugged the solenoid back in for a few hours the other day (I had to reschedule my trip to the dealer because of inclement weather), it seemed to "reset" everything more quickly that when it adapted to being unplugged. Because I rescheduled for Monday, I unplugged again and the adaptation had to occur again, though much faster. The retrograde change from plugging the solenoid back in was so noticeable that I had to doublecheck that I reloaded my tune correctly (which I had). But things (i.e., performance) quickly returned to "normal" (prior to plugging back in).

 

Not to point fingers but I want to say CaliBenz has used language suggesting that Bosch makes specific, independent calibration decisions. I have assumed that's a language thing and I know what he means, but I think others interpret more literally which can be confusing.

 

Sorry for bring Bosch into the discussion, but it's merely a distraction from the main point: Is the 3500 RPM trigger a variable value that can be changed in a look-up table, or is it hard-coded? I'm not a software guy (like @CaliBenzDriver ), and I don't even play one on TV, but I know enuff to think that a hard-coded value must be changed in the source code and recompiled. I think using something like Vediamo or DTS is just adjusting variables, but I could be wrong there. My last programming was in FORTRAN.

 

While I definitely want the delve into whether a tuner/coder can change these variables and associated functions to possibly improve ECU and TCU tunes.
For the mod itself, I definitely would rather the entire connection not be present to actuate the solenoid at all. It's just a personal preference, but that's the only way to ensure it's not doing it's terrible job.

And yes, Cali really likes to espouse the Bosch system as being pretty good in most areas, especially for the age of the system. It's definitely a well written system that can adapt to many engine circumstances to try to keep best performance, thus why this mod has been so successful.

 

I have a possible path at the bottom...

Here I was paying attention to jury duty instructions while replying to a hack question:
I have too much respect for a working computer then to tamper with its software. The executable code compiled for the target CPU is virtually unmodifiable, even by the original team that wrote the source.

We are not talking about an HTML page... we are talking about MBytes of instructions of proprietary software. To modify object code requires the proprietary source tree before it gets packaged.


> Maps vs. Logic:
Mixture Maps can be modified because there's a whole cottage industry and hacking tools to rework these tables with different offset values.

Understand that tempering with the logical processing code is not on the horizon.


> Finite ressources:
Days are 24Hr long... I am biased towards working solutions. This translates into this statement: pulling the solenoid can be a free 5mn job to completion easily reversed
vs.
Pioneering the impossible taske recoding a working ECU. I bow to that!!


> PATH to SW TWEAKS:
Ok now that I'm thinking, how about this:
One free way to go get lucky is through the exposed settings. This doesn't require to brake any executable binary code. Related options are either exposed or not exposed. Finding these SETTINGS is the KEY HERE! It is still very possible to mess up the ECU with messed up inputs.

I don't believe 3500RPM is going to be offered as a setting but perhaps Active/Inative basic toggle.

I don't think this range of deep settings are going to be available... the hunt is on: Vediamo/Monaco gurus... Look up options under engine control module.

We want to run the solenoid PWM such that
-- ECU knows pp solenoid is plugged in factory condition.
-- ECU does not activate low pressure pump output
-- Test options to be sure of preliminary results.


> High cold start idle correlation:
Ppl expect miracles, plurial. At least you got the first one soon after unplugging.
Further miracle comme tied to first stage then reaching second stage then another stage where door pops open - very much like the Russian doles.

The cold start idle is like a live VVT shift activation test. The RPM and length won't improve until your engine mechanicals improve. We looked earlier at steps to help the engine run seriously well.

✌️

 

Does HP Tuners have support for these MED177s or whatever they are? Or just ME97?

 

Some of you wont like my reply, but mine made no difference. Well, it did make my oil leak worse...
I also adjusted my cams back to stock to see if that makes any difference, and it didnt. Soon I will be loading the oem tune, to get a smog, so we'll see if that gets a reaction. Since I know its not VVT giving the gains, at least in my car, it leaves throttle responseq which is no doubt a result of torque control. Since some say it netted more torque, it makes perfect sense.

 

Heretic! J/K

What kind of tune do you have? I have a Stage 2 that just never ran well before. Disabling the solenoid allows me to run the Stage 2 file without any negative effects.

Are your readiness codes never set with the tune? Is that why you're loading the factory file?

 

Red; HP Tuners, so it's my own tune.
I heard a rumor they're doing checksum checks to catch tunes, which I'd fail. Even if they are not I'd still be better to use the oem, which is easy to load up.
Yes I do have a readiness check issue; Evap System - Incomplete It appeared some four or so months ago and won't go away. My gas cap seems fine, but I cleaned and lubed it with fingers crossed., Still fails. I guess I'll get a new cap but I doubt it'll be that easy.
I have an O2 Heater fail readiness as well, but with a little tweak in the tune, more stockish on cold start, I can make it go away.
My oil leak is apparently on the valve cover, which drips on the ex manifold. I dread it because I have to pull the fuel lines. If I didn't floor it then no leak, or at least I wouldn't smell it. Now I smell oil all the time and it's worse than ever.

 

OK, your readiness "incomplete" may be just because of the tune. I have the same problem, so I always need to reload the factory/OEM tune before emissions testing. After that, readiness is almost immediately "complete".

Your increased oil leak may be coincidental. I would check your PCV valve to see if it is working correctly because the whole purpose is to relieve pressure and recirculate vapors to be consumed in the combustion process.

Check this thread: https://mbworld.org/forums/c-class-w...ml#post8909191

 

My Evap valve in the engine bay had a torn rubber elbow.. may be something to check.

 

I've been messing with tunes for two years now, and it was fine before, so I suspect it's mechanical? I really don't know for sure, just assuming... Heck, I don't' even know how it knows if it's "ready" or not. Like one Benz I had said the EGR was bad, yet it was not. How do you fix that? You don't, and I sold the car as parts car because it wouldn't pass smog for that reason. This is one of many reasons I hate electronic bs, it's too stupid to work right and you can't see it to fix it.
I think I have too much ethanol in it now to load the oem tune, but I suppose I could try. Worst thing it'll do is not run.

Seigmann; good idea! Where is that elbow, and is the valve in the same spot? I had assumed the valve was in back. Plus I recall cycling it in Xentry and I could've swore I heard it in back? Anyway, I looked online and not much luck. One said it was behind the right rear tire, but it was not a 207. I can't find squat for a 207. I'd assume yours would be more or less similar and in the same general location, but just a guess.