[Benniese90]

Has anyone ever seen this?

Ista shows all the ecus, but one is in red and not communicating. But which ecu is it? How fo I find out what the ecu is so that I can go to it and troubleshoot it. Maybe check its fuse relay connector etc. All is gives me is the serial number. Heres a picture.

The car is a 2011 335i n55 engine e93 convertible.

Thanks.

[TunafishE93]

You mean your DME?

[Benniese90]

No the DME is there its in yellow in the picture because it has misfire error codes.

The one in red at the bottom left in the picture is the one im trying to identify so I can troubleshoot it.

Thanks.

[F31B48]

That is not an ECU. If it was an ECU it would be up the top with all the others and it would be connected to the "control unit tree" What is the issue you are trying to troubleshoot?

[Benniese90]

well its some module or circuit nthat isnt communicating at all. The issue im having is multiple misfires, power loss, and a valvetronic code. No valvetronic reset is allowed no matter how i try to do it. I will post some more pictures of the codes and some readings. I believe that the module/circuit is some controller much like the fuel pump control module that controls the valvetronic motor and by that not operating at all its causing the misfires and lack of power. It has a new starter, alternator, battery, plugs, coils, maf sensor, cleaned injectors and replaced teflon gaskets, cleaned intake valves, checked every single connector and wire on the engine, checked all of the fuses and relays i could find except the possible relays some say are soldered to the back of the fuse box panel. Im also wondering about the high pressure fuel pump as i get a code on a cold start sometimes. But I zeroed in on this module or whatever it is thats not communicating. I have Ista+ Ista P, BMW Standard tools INPA, and a schwaben foxwell tool, I have a bimmergeeks cable and a BMW ICOM cable. I am very new to Ista so bare with me please.

Any ideas?

[F31B48]

It's not a module. The DME controls the valvetronic. Just concentrate on the DME codes. How did you clean your injectors? Have you run through the test plans for the fault codes with ISTA? It will tell you what to check/test. There is a box on the bottom right of the fault code screen that says "calculate test plan"

You may also have a HPFP issue which will cause misfires

[Benniese90]

i will try the calculate test plan but i believe ive already gone there already. Ive been through so many side tangent that its a bit of an overload of information sometimes.

The injector cleaning....I described that in detail in another thread i started titled "HEEEEEELP PUUUHHLEEEZZEE N55 DOWN" and that thread gives way more information on the actual problems im having but heres a copy of the injector excerpt from it:

On the injector cleaning, heres what i did, dont judge me...it does work as ive done it sooo many times in the past with great results:

Remove injector carefully, keep them in order, anytime you handle them, handle with care to protect it, then spray tips with contact cleaner spray and wipe as much of the black carbon off as you can with a paper towel, then (optional) you can let the tip sit/soak in a shot glass of injector cleaner for awhile...longer the better then wipe again. At this point almost all or all of the black carbon deposits will be gone from sight. Now get a 9v or 12 volt battery and use alligator clips to hook up the injector but dont apply power just yet to it. (NOTE: THESE ARE THE SOLENOID TYPE INJECTORS, NOT THE PEIZO ONES) The you can either attach a water hose or a water bottle to the injectors threaded inflow port. This next part takes some coordination but is doable. Apply your water flow by turning on the hose or by squeezing the water bottle.....as you are doing this begin tapping the connection to activate the injectors solenoid. As you do this you will see the injector spraying water out of the holes. Keep doing this until you see the water spray out in a star shaped pattern as there are six tiny holes in the injector tip. Doing this will ensure that the injectors tip holes and insides are unclogged from the wiping or any other reasons. Then you reinstall it.

Im thinking im gonna replace the low pressure fuel pump and maybe the regulator since its not that expensive of a part to eliminate. My logic is that maybe the low pressure fuel pump can be starving the high pressure fuel pump causing it to not have enough fuel run all injectors properly thus causing injector shut down misfires.

There is no low pressure sensor on a n55 engine so i cant test that. Also when its in that very rough running idle state I can pump the accelerator peddle and alot of the time it wont even increase the rpms at all as if the fuel pump is not getting the signal to increase output.
Ista shows that the fuel pump control module is perfectly fine all green. No codes. But the low pressure fuel pump pressure readings in ista read 600kPa. they do not fluctuate at all never. But when i use ista to look at the high pressure readings....they fluctuate from 15.1 to 15.8MPa...so im inclined to think that its doing something but not the low pressure fuel pump.

On top of all of that issue I have the valvetronic motor. I am with you on the DME controls its operation but for some reason its not controlling it or its not responding. It makes a rapid fire burst of clicking sounds sometimes upon insertion of the key but thats about it. If the valvetronic motor or the eccentric shaft sensor fail completely will it cause the misfires and loss of power or will it still be driveable? curious.

With all these new parts on it and all of the service done on it, I believe its something simple that im missing like a part but i dont wanna just throw parts at it....i would like to diagnose the correct part or parts to replace.

Thanks for any ideas or insights into any of these issues. Another mind looking from the outside is often what a person needs to finally have that "ahh ha" moment.

Thanks for anyone who has read this.

[F31B48]

There is a test module you can run in ISTA that will test all of that for you so you don't have to guess and replace things.

There is a low pressure fuel sensor on the n55 according to the ISTA diagram I'm looking at for the n55. Its only n51 n52 that don't have a fuel pressure sensor. The sensor is under the intake manifold, just behind the HPFP. You should be able to see it through the gaps between the intake manifold runners. ISTA could be wrong of course, in this case you should test it manually with a pressure gauge. Run the test module for the high pressure fuel system first before replacing anything.

You can access the test modules as follows.
Select "vehicle management " tab
Select "troubleshooting" tab
Select "function structure" tab
Then select "drive"
"engine electronics mevd"
"High pressure fuel system"
Then select "start search" on the bottom right of the screen
Then select "ABL Fuel system"
Then select "display" on the bottom right of the screen.
Follow step by step instructions on the screen from there.

[Benniese90]

I will try that the next time that im over there where the car is. Thank you for your time and help.

[dpaul]

Originally Posted by Benniese90

There is no low pressure sensor on a n55 engine so i cant test that.

But the low pressure fuel pump pressure readings in ista read 600kPa. they do not fluctuate at all never. But when i use ista to look at the high pressure readings....they fluctuate from 15.1 to 15.8MPa...so im inclined to think that its doing something but not the low pressure fuel pump.

The TIS wiring diagram for your VIN (E260879 on your ISTA screen shot) shows a low pressure fuel sensor but REALOEM does not. I'm not very familiar with the N55 but it may well be that you do not have a sensor - you'll find out for sure soon enough with a visual inspection.

The thing I found curious was your report of rail pressure of 15.1-15.8 MPa (2190 psi - 2291psi). Those are reasonable numbers for an engine under load but at idle you would expect about 870 psi (5.9 MPa). Were you reading that pressure at idle?

[Benniese90]

Thanks dpaul, yeah everything ive read says the n55 doesnt have a low pressure sensor at all.

Those readings were taken at idle. Well, if you can call what it does an idle.

It idles at about 500rpm and it has a really rough idle and engine power loss. The engine shakes pretty badly and it shuts down several cylinders which is probably why it is rough and shakes because all cylinders arent firing due to the computer shutting them down for some reason.

I can reset the misfiring codes and it immediately will shut them back down again by way of turning off the injectors.

Thats why im suspecting a fuel flow or fuel supply issue.

Its very frustrating trying to pinpoint this issue so that i can fix it. Its really hard to fix it when you cant pinpoint the exact cause so I am at a loss for right now unless someone else can shed some light on it.

Thank you.

[Scoff123]

Hey, out of interest what version of ISTA are you running? I only ask as I've recently updated to v4.29.30 and I too have a strange red box showing what looks like an error, just like you have in your first picture - a red box showing _0xA0



I've never seen that before, when I used to use a much older version of ISTA, v3.xx but I'm not sure what it actually means.

[Benniese90]

Wow, thats very interesting. I too, am running the same ista version4.29.30.

I wonder if its the version or if we have something similiar going on.

What version was it that you used to use?

I will download and install that older version and try it.

It just takes about 2 hours to download it and then another 2 hours to install it. Then maybe an hour to figure out the correct com and port settings. But I will try your older version to eliminate this newer version from being at fault.

And thanks for the possible insight.

[dpaul]

Originally Posted by Benniese90

Thanks dpaul, yeah everything ive read says the n55 doesnt have a low pressure sensor at all.

Those readings were taken at idle. Well, if you can call what it does an idle.

It idles at about 500rpm and it has a really rough idle and engine power loss. The engine shakes pretty badly and it shuts down several cylinders which is probably why it is rough and shakes because all cylinders arent firing due to the computer shutting them down for some reason.

I can reset the misfiring codes and it immediately will shut them back down again by way of turning off the injectors.

Thats why im suspecting a fuel flow or fuel supply issue.


Its very frustrating trying to pinpoint this issue so that i can fix it. Its really hard to fix it when you cant pinpoint the exact cause so I am at a loss for right now unless someone else can shed some light on it.

Thank you.

Your rail pressure is abnormal - abnormally high. It would be very helpful to get real time readouts of fuel trims and AFRs to see how the DME is trying to compensate for that condition.

As you may know, the HPFP is driven by the engine so it's speed is directly proportional to engine speed. To regulate rail pressure, a fuel control valve, operated by the DME, varies the amount of fuel going into the HPFP. The pressure is monitored with a sensor at the fuel rail.

The pressure you are seeing at idle is much too high and might explain some of the crazy low speed bullshit you are experiencing - too much fuel, beyond the ability of the DME to compensate correctly. A look a the fuel trims would immediately tell you if this hypothesis was valid.

You can get that info from ISTA or probably your hand-held scanner
From ISTA: Vehicle information->Control unit tree-> Select DME->Call up ECU functions->Diagnosis Scan->select Oxygen sensor control. Read additive and multiplicative mixture adaptations for both banks.

None of this explains your Valvetronic fault code, however.

[dpaul]

Originally Posted by Benniese90

Wow, thats very interesting. I too, am running the same ista version4.29.30.

I wonder if its the version or if we have something similiar going on.

What version was it that you used to use?

I will download and install that older version and try it.

It just takes about 2 hours to download it and then another 2 hours to install it. Then maybe an hour to figure out the correct com and port settings. But I will try your older version to eliminate this newer version from being at fault.

And thanks for the possible insight.

I don't think you have to worry about that right now. It's not an issue for the diagnosis your need to do (or probably any ISTA function)
.

[Scoff123]

Yes exactly - stick with your current version of ISTA as it seems to be working fine - if I find out what the _0xA0 red box relates to I'll update this thread as I'm just curious!

[Benniese90]

Thanks.... Oxygen sensor control. Read additive and multiplicative mixture adaptations for both banks.....omg i ran all of them EXCEPT that one. I saw it many times going back and forth I just didnt run that one.

I will run it the next time I go to the car...probably tomorrow.

Today im going to pick up the low pressure fuel pump and have it ready for tomorrow so i can do both.

Fuel pressure way too high......you might be onto something there because I have not driven it at all since this extreme power loss began. I have just started it and let it idle. Or sometimes pushed the gas pedal down to get the rpms up a bit----although sometimes the gas pedal does nothing and the rpms will never go beyond 4000rpms no matter what.

However, with just operating it at a standstill i went from 3/4 of a tank of gas to less than 1/4 a tank so its eating up gas very very fast.

ON the valvetronic issue....its definitely a concern but it shouldnt stop the car from being driveable even in a full failure situation. And both of these issues showed up at the same time.

ON the ista version.....yeah i dont know. I can get ista to work with my bimmergeeks kdcan cable but i have an ICOM cable and no matter what i cant get the icom cable to read. I only care because the kdcan cable cant program it seems and im told that the icom does more and has more diagnostic capabilities. So idk.

[dpaul]

Originally Posted by Benniese90

Thanks.... Oxygen sensor control. Read additive and multiplicative mixture adaptations for both banks.....omg i ran all of them EXCEPT that one. I saw it many times going back and forth I just didnt run that one.

I will run it the next time I go to the car...probably tomorrow.

Today im going to pick up the low pressure fuel pump and have it ready for tomorrow so i can do both.

Fuel pressure way too high......you might be onto something there because I have not driven it at all since this extreme power loss began. I have just started it and let it idle. Or sometimes pushed the gas pedal down to get the rpms up a bit----although sometimes the gas pedal does nothing and the rpms will never go beyond 4000rpms no matter what.

However, with just operating it at a standstill i went from 3/4 of a tank of gas to less than 1/4 a tank so its eating up gas very very fast.

ON the valvetronic issue....its definitely a concern but it shouldnt stop the car from being driveable even in a full failure situation. And both of these issues showed up at the same time.

ON the ista version.....yeah i dont know. I can get ista to work with my bimmergeeks kdcan cable but i have an ICOM cable and no matter what i cant get the icom cable to read. I only care because the kdcan cable cant program it seems and im told that the icom does more and has more diagnostic capabilities. So idk.

You don't need the ICOM. Only for flashing (not coding- flashing means replacing all the program code) and only for flashing MOST bus modules, do you need ICOM.

[Benniese90]

oh wow thanks thats good news. I have been reinstalling different versions of ista to try to get one of them to work with this icom but i guess i dont need it really. Thanks for that. As soon as i run those tests in ista i will post back with the results on here.

[dpaul]

Originally Posted by Benniese90

oh wow thanks thats good news. I have been reinstalling different versions of ista to try to get one of them to work with this icom but i guess i dont need it really. Thanks for that. As soon as i run those tests in ista i will post back with the results on here.

Here's another thing to check - injector leaks. Pull the spark plugs after the engine has been sitting without running for a good while, for example, sitting overnight. Do you they look 'wet' - can you see/smell gasoline on them?

[Benniese90]

Thanks...yeah ive checked the spark plugs for fuel smells or wetness multiple times with no signs of leaking. With all of the misfiring and rough running they do get fouled pretty quickly...all of them except cylinders 3 and 4. those 2 spark plugs stay pretty clean for some reason.

So I ran the oxygen sensor multiplicative test you suggested... I am attaching pictures of the results. I dont understand why it doesnt seem to give me any fuel trim information for bank 1 and bank 2. I used the ista to get these values while it was rough running but idling at about 500-600rpm. I also used my foxwell to get the readings in the pictures.

Of interest is: specified speed, fuel pump 5315rpm
actual speed, fuel pump3635rpm

I also notice that the fuel pump has 0 current. Shouldnt a motor be pulling some current if its working?
Im going to pick up the low pressure fuel pump and its pressure regulator tommorow. Then I will install it maybe monday just to eliminate it as a contributor of evil. lol

Maybe someone can make some sense out of these readings. Im coming up with nothing.

I swear someone should create a diagnostic program that says: DUDE, its your fuel pump, replace that thing now! ---or----Bad news bro, you gotta get another DME.

Anyhow, here are the pictures.....

[F31B48]

Originally Posted by Benniese90

I swear someone should create a diagnostic program that says: DUDE, its your fuel pump, replace that thing now! ---or----Bad news bro, you gotta get another DME.

There already is a program that does this. ISTA. If you follow the test modules that ISTA lists for your fault codes and do all the tests properly that it says to do, at the end of the test module it will literally say "replace high pressure fuel pump" or replace " crankshaft sensor" 90% of the time it is accurate.