DaleB

Let us assume for a moment that I want to replace the ECU in a 2007 S600, using a used ECU (same part number) from a donor vehicle. What's involved? Can a used ECU be coded to work in another car, or not? Does it need to be replaced along with any matched components? What are the pitfalls here?

I'm asking because the last time I assumed that a used part (ABS controller, to be exact) could be successfully installed in another car, I was wrong, and wasted a couple hundred bucks and a whole lot of time. I've got an issue that is growing worse, and the ECU is one of the last few parts that seems like it could possibly be involved that hasn't been replaced.

The symptom: Whenever the car sits with the ignition off for more than a few minutes, the starter will spin the engine for several (4-5-6) seconds before it starts. Once it finally does start, it will usually run very rough at a low RPM for a few seconds before achieving its normal idle RPM. It will often throw multiple misfire codes during that time, several cylinders in both banks (1,2,4,7, and 12 if I recall correctly). If you stop the engine and re-start after a few seconds, it starts perfectly normally and idles smoothly. The car otherwise runs strong and smooth, with no performance issues.

Crankshaft position sensor is new.
Camshaft position sensor is new.
All spark plugs are new.
Both coil packs are new V12ICpack rebuilds.
Fuel pump has been replaced.
NO other engine related codes have ever shown up
NO changes in behavior since starting to troubleshoot this, to include the cylinders identified as misfiring.
Turning the ignition on and letting it sit for a while before cranking makes no difference.
Fuel pressure at the rail is 52-54 PSI.
I've pulled the front SAM and ECU and checked for burnt, dirty, corroded, or otherwise imperfect connections or wires and found nothing amiss. No signs of moisture in the box either.

The extended cranking was an occasional thing a year ago. Within the past few weeks it's gotten worse. It's now happening 100% of the time when the car has sat for more than 5-10 minutes with the engine off.

Plutoe

Why do people always do things *** backwards with MB's-----No you cant just swap the same used part number because the used ECU has someones else's VIN. You have ask a tuner or someone with special software that can edit the ECU and place the correct VIN. Also be careful as some Mod years also have the TCU encoded with the original VIN.

Think of another project, like mud flaps!!

DaleB

Thanks, pal. Very helpful. I know you can't just drop in another ECU. What I was asking -- oh, crap, yeah, it's right there in the original post!! Maybe reading it would be helpful.

Next contestant, please.

MBCO

Dale. You did not deserve the tone of the prior response, so in a friendly way (with caveats I do not own a v12) to answer your question on pitfalls, DAS Xentry will need to be involved. Do you have access? A thorough diagnostic will confirm your suspicions OR lead you to solve other gremlins. If you need it, some forum members can do coding remotely. ECU changes are not for the faint of heart. Good luck and keep us posted.

DaleB

Some people just like to act like jackasses.

Yes, I have DAS. Diagnostics have proven to be less than helpful in this case - according to DAS, everything is perfectly fine other than stored misfire codes as noted. Actuations, tests, all fine as long as the engine is running, or has recently been run. The issue only occurs when starting after the engine has sat for a while, and the only codes that occur are misfires on several cylinders immediately after startup when it's idling very rough. after that nothing is wrong.

And yes, I know there will be coding needed. But my original question still stands... can a used ECU be re-coded to work in this vehicle using DAS, or not? And if not with DAS, can it be done at all?

auburn2

If I were going to throw parts at it I would try an ignition voltage transformer before a new ECU. I think there are DIY places you can actually rent the voltage transforment and try out a new one and if it fixes the problem you ship your bad one back for rebuild and they charge you. If it does not fix the problem you ship back the one they sent and pay only a small rental fee.

DaleB

I've been talking to Clark at V12ICPack.com for a while, and we're both pretty sure it's not that. It was one of the first suspects on my list. Unfortunately he doesn't have one available for rent right now, so swapping it out isn't an option.

I don't really think it is the ECU at this point. It was raised as a possibility the other day by someone who currently has a very similar issue with a CL600. If it were the ECU, I'd expect it to only happen when the car is cold, OR only when it's hot -- that's not the case, it happens both hot and cold, as long as the engine has sat without running for more than a few minutes, and only on the first start. If I shut it down and re-start within a few minutes, everything is fine. Of course that failure mode in a device like an ECU is not inconceivable, but it would be unusual.

MBCO

Dale, can you hook up DAS In circumstances you describe in order to capture the rough start and misfire “live”? If you can video the event it may help you hear something as well? I read on Mercedes medic an article on DAS where they described a “green key” necessary to recode ECU. That in itself if true tells me programming a donor ECU is possible. Let me know if you need the link.

pmercury

iTrader: (2)

Not as it
It has to be virginized before adapting
then in some cases, if you can read old ecu you can use "code with takeover" in Xentry
if you can"t properly read the old device you'll need to have someone like me do online coding
but this is not possible if you have a old das or xentry

then a last solution is possible with vediamo

MBENZTECH

Hello DaleB.... the used ECU first has to be virginized and only then it can be coded to the car. If you send me the Original ECU along with the Used/new one I can do everything on the bench. It will have the latest software update/SCN coding done with connection to the server. I will have all FBS3 data transferred from Original ECU.

Minh

I think you need to check the fuel line, perhaps the fuel line is not well connection cause fuel loss presure when engine stop. You need to check fuel pressure wheen engine stop to see wether the fuel pressure is drop or not.

DaleB

The event is so short lived that there isn't much to see. I suspect being able to produce a datalog of everything -- or at least a few selected parameters, like position sensors, commanded fuel, fuel rail pressure, commanded spark, feedback from coil packs, that sort of thing would be nice, but I don't know that DAS is capable of that sort of thing. The only thing DAS does show is the misfires, after it eventually starts. I got one of the less severe events on video over the weekend.


Thanks, that was helpful. For the record...Yes, I understand that one cannot simply plug in a used ECU from another vehicle and expect it to work, and if it is possible at all it would require some re-programming. And that's what I have been asking, is C A N it be done, and of so W H A T is involved.

The old ECU is fine, as far as I know. I can read everything out, but my question was whether the "code with takeover" could be done on a used one, or only with a brand new ECU. I know there is at least one module that simply cannot be used on another vehicle, ever, period, at least not using DAS or any other tool that anyone I could find has. Didn't know if ECUs were similarly irrevocably married to a car once installed. I know there are some anti-theft factors but don't know the details, or if there's a "Yeah, it will work but you also need all the keyless-go and door modules from the donor car" or some similar gotcha. The reason I asked was that someone else with whom I've been corresponding has a similar issue, and he's sent his ECU off for testing.

At this point, though, I believe it's become just an academic question. After another couple hours of troubleshooting I'm thinking that this is not ECU related at all, but something as mundane and simple as one or more flaky injectors leaking fuel into cylinders and causing a flooded start. Saturday I spent some time with the laptop looking again at fuel pressure, including a lengthy idle fuel pressure leak test (no surprise, rock solid and fine). For the first time, though, I was seeing repeated and fairly frequent misfires at idle. I had FELT them before, but never seen them show up in DAS while I was troubleshooting. I'm running some injector cleaner though the fuel system now; we'll see if that has any effect at all -- good or otherwise. If it turns out to just be some gummed up injectors I'll be very happy. I'll be even happier if some Techron clears this up so I don't have to pull the fuel rail. I'll be surprised, as I've honestly never had a vehicle have injector issues, and I've been driving FI cars since the 80s (if you count TBI). This one has always had alcohol-free premium gas from major brand stations, but it did sit most of the winter without being driven much. We'll see what this next week brings as more cleaner gets run through the fuel system.

When the engine cranks I see the fuel pressure come up to about 54 PSI (3.7 bar) immediately, and stays where it should be the entire time the engine runs. After shutdown, the pressure will slowly bleed off. A week ago it was bleeding off quite quickly -- a couple of minutes to reach near zero. Now it's much more slow to bleed off, which tells me I may be on the right track.

antiguangenius

if you send me the donor I can make it happen if you have das, if you don't have das I need both ecu then it will be plug and play

pmercury

iTrader: (2)

you can not virginize that donor ecu with DAS
it must be virgin first. nothing will happen

DaleB

Just a quick update. The symptom (long crank, slow start, random misfire codes, etc) was a simple case of gummed up fuel injectors. :But hey," you might ask, "how come you're dumb enough you never thought of that?" Well, in all my years of driving fuel injected vehicles, I've never once seen this happen before.

Several bottles of fuel injector cleaner (Techron and Red Line) and a 1,000 mile road trip later and the problem is almost completely gone. Zero starting or driving issues. The only remaining issue is that if you floor the accelerator (which is always a joy in an S600), it with throw a misfire code and shut down cylinder #9, every time. I'll give it one or maybe two more tanks of gas/bottles of injector cleaner; if that doesn't fix it, I'll take it to one of the highly recommended local shops and let them pull the fuel rail and IRAN the injectors.

Now on to those gummy steering wheel buttons...

pmercury

iTrader: (2)

And don't forget that with the W221, for those who change the injectors on certain models, you must note the new injector trim 6 digits codes by cylinder before install !
these numbers must be entered in the engine ecu module with Xentry to get a perfect engine

WHY TRIM CODES ?

Theoretically, if any 10R4761 injector will fit the same way as any other 10R4761 injector, they should all have the same output. They are all made the same way, after all. But due to slight differences in machine tolerances, friction between parts, and magnetic forces, some injectors have different rates of output. By using trim codes to adjust the injection duration for each individual injector, the net output of the injector for each cycle is the same in an engine.

When some manufacturers make these specific electronic injectors, they put them on a machine to test for the correct fuel output.
If the output is not exactly within the specification range, the computer will generate the code to control the current so that the net output is within spec.

Here in this case I worked on the injector numbers disappeared with Firmware upgrade
S550 4-MATIC 2012
Unfortunately the original build numbers on file in the MB servers in Germany where too short.

Waiting to remove each injector, read the number, I managed to type standard numbers in the ecu but it didn't help to remove the fault

Online SCN coding didn't help either

so be warned, read the numbers un certain models before you upgrade this ecu firmware !

MBENZTECH

The engine in this S600 is the M275.953. It is a manifold fuel injected engine. There is NO NEED to write any injector coding. Here is the part number A2750780249.

antiguangenius

who said I was using das?? I have been doing this for years buddy, google autodadgetsnyc

or can have a look here

pmercury

iTrader: (2)

On a S65 you do have this and its always better to note them then getting a message xentry after you installed them. as you can only read them by removing them
I will post a screenshot later

pmercury

iTrader: (2)

nice !

It was just that you asked him if he had Das so I was thinking you dreamed of using Das to virginize a ecu instead of a
3 min Job with Arbrites or using a simple cheap programmer and a clamp to set the first bytes to F or 0

Just a misunderstanding

antiguangenius

No I was saying that I can do the first part then with DAS anyone can adapt to EIS

pmercury

iTrader: (2)

My post above has been updated

vettebk

Hi Dale,

Have you replaced the ignition control module at the top of the engine? When they start to go, they usually throw one or two misfires under load and run crappy. Sometime a restart will clear it temporarily. Clark writes about it and you can do a rental swap with him for the module just like the coil packs. If your coil packs are good and you are getting a misfire, I would look at that ignition module. Good luck.

MBENZTECH

Again, the engine installed in DaleB’s S600 DOES NOT need injector coding. It uses manifold injection. You’re trying to prove a point that does not need to be proven. The whole point of helping is to provide the correct information according to their vehicle.

ItalianJoe1

This issue was a function of fuel boiling on my 600, there is an ancient bulletin about it, I updated to the parts listed which are basically the fuel pump controller from a 65 along with a new pump and filter and such, solved the issue for me. Glad to see yours got better with driving it and fuel cleaner.