NefMoto

I have a 3B0907551G box sitting in front of me, and I really really really need a 8D0907551M instead... Can I flash this one? I believe it is  ME7.1...

It will not work, no.

Thanks!

Can you tell me why it won't work?

Will it flash? Yes. Will it run? Yes.

HOWEVER, it will have no concept of boost control, it will misfire at regular intervals, and run poorly. The ecu's are different from a hardware standpoint.

Thanks for the explanation. I was under the impression that "an ME7.1 ecu is an ME7.1 ecu is an ME7.1 ecu" - that each one was essentially the same and could be treated like a blank canvas. You learn something new every day.

I just flashed a mbox file to a passat 2.8L ME7.1 ECU
I flashed fine and ran in the car.
I only test started it and never actually drove the car, or logged it.

Was just a experiment while I was bored one day.

f1torrents, your response and a few other things I read elsewhere piqued my curiosity, and so I tried it.

And guess what? IT WORKS! It works beautifully! I have flashed three different M-box .bins to it and tested each one.

I first read the ECU to make sure there were no issues with it prior to flashing. After flashing the first file, I read the ECU and compared values. I found that even the Bosch hardware number had changed from 0261206113 to 0261207143 - so far, so good! I then used VCDS to map both adaptation channels and measuring blocks, and compared the maps to what I had saved from working on other M-box S4s. Next I ran output tests to make sure the N75 and N249 solenoids were functioning, all good there. Started the car, let it adapt. As it warmed up I kept my eye on misfires (there were none).

On the first drive, a pair of bad EGTs and a bad secondary O2 sensor reared their ugly heads. I swapped in some EGT deletes, but still no change, still showed short to ground... hmmm... a quick edit, remove EGTs and rear O2s, and bingo, we are in business!

Finally, I flashed a modified performance .bin and the car is boosting to 22 pounds and running strong!

I'm now curious if the DBW 30v 2.8 ECU only differs from the S4 in terms of EGT support, or if my EGT deletes are indeed bad.

Whoa.

(http://img3.wikia.nocookie.net/__cb20130816013736/vampirediaries/images/3/30/Fry-can-t-tell-meme-generator-not-sure-if-sarcasm-or-serious-e14739.jpg)

No, I'm serious, I had no idea you could do this! I assumed (like DD) that the ECU was entirely different.

When I tested mine the turbos 100% spooled up.
It did not studder or misfire.
I ran it for a few miuutes in neutral and it seemed fine.

I will run and log it on saturday.
BTW I had deleted 02's EGT's SAI, EVAP in the file.

I have tried this personally and had issues.

Here is a link to noob Daz, who tried the same thing when he realized NA ecu's were dirt cheap:

http://nefariousmotorsports.com/forum/index.php?topic=2697.0

It's worth noting it seemed to run decent, but it DID show misfires on blocks 015 and 016 at idle, whereas the stock ecu did not.

Like I said, will it start and run, yes. Will it work properly, no.

I cannot speak to anyone else's experience; all I know is what is and is not happening in my situation.

I have been working on this all day - nonstop since 9 this morning. It's now almost quarter after 4 in the afternoon, and I have yet to see one misfire pop up or hear the motor stumble. On my other S4, parked directly behind this one, I have an off-the-shelf MTM stage 3 tune, and that car racks up the misfires at idle - not only do they add up in VCDS, but you can hear and feel them. Both cars have the most recent revision FSI coils, though this particular car has the appropriate harness wired in while my other S4 has the 034 kit (what a mess).

Anyway, so far with all my runs and 3rd gear pulls and logs and butt dyno sessions, the only hiccup so far has been the TBB blowing off the throttle body once... 2 miles from home and had no tools, unplugged the MAF and she ran like a champ all the way home.

I will do some tests and logs on Saturday.
Hopefully we can confirm if this works or not.
My initial test seemed promising.

Daz, maybe your ECU from back in the day was bad? Or something in the e2p was wrong?

We shall see...

IDK man, the ecu I tried is still alive to this day in my buddies car, so I doubt it very much.

I looked at the boards. There are a TON of missing resistors, and even more with different values between the two. There's no way I'd trust it.

Humm.
I haven't looked at the differences.
It does seem to good to be true. And usually in that case....

Well, I look forward to what f1torrents has to say on Saturday. I ended up putting 75 miles on the car today, with the only problem I had was blowing off the stupid TBB, twice. Really need a set of APR pair of bipipes for this car...

Tomorrow I may head over to the junkyard and see if I can't scrounge up a couple more of this p/n. They usually have a few 2.7T A6s there as well, we'll see what I can find.

Update: I picked up 4 30v ECUs at the junkyard yesterday, two 3B0907551CGs, a 3B0907551AN, and a 3B0907551BS. There was a single '00 A6 2.7T in the yard but someone had snagged the ECU already. The AN box was the only one without an immo, but I flashed a clean 95040 to all of them and systematically tested each on both S4s (one stg 2+ '01 and one full stg 3 '02) and...

Not a single problem with *ANY* (EGTs deleted) file on either car! No misfires, no CELs, no EPC lights, no troubles. However, any files with EGTs trigger limp mode and set 17866, 17867 DTCs once the coolant gets to temp.

So, if you are using EGTs in your particular setup/tune, you won't be able to use the 30v DBW ECUs. This is the only definitive answer I've come to, though it's looking more and more like the rest of us can use these cheap and plentiful ECUs.

I'm going to continue exploring this development. If you want data or logs or anything, just ask.

I was super busy today and didnt have a chance to do any testing on the s4 with my 2.8L ECU.

Well I did some tests today and it's not looking good.
No codes present at all.
No misfires
Smooth idle and drive

However the n75 control was the issue.
It went from 0.0% to 95%
There was no smooth tradition. Just a massive jump.
The boost would not keep up with specified.
It would boost but it was way off and it was obviously down to the issues with
controlling the n75.

Once I noticed that I stopped and pretty much placed this idea in the dead pile.
The ECU will work in a pinch if you are stuck or stranded.
but not reliable for anything other than that.
DD you are again, correct. :)

We should never doubt you....

That sounds completely normal as far as DC shooting to 95% without transition.

I'll post my logs tomorrow. I've had zero issues with the N75 duty cycle  :-\

I wouldn't doubt there are many different 2.8 ecu's.

I'm not making things up here, I had ACTUAL problems running one in my car. I spent HOURS measuring, and transferring components from a dead 2.7t ecu onto the 2.8 one.

It was never anything I'd trust using.

Actually, here's one from my stg 3 car from last Sunday after I adjusted the wastegates back down to 9 psi. Just a quick up the road and back.