[Twinsical]

Hi there, so a few days ago my car decided it didn't want to run nicely anymore. Plugged in my icarly and I've been met with a whole host of error codes and the engine is misfiring horribly from start up, revs are not stable at idle and the car basically won't move.

So when I initially had this problem i was stuck at some traffic lights, had to call the RAC to get towed and then I just decided to try starting it up once more and for whatever reason all the problems went away and I managed to drive it the 1 mile journey back to my drive where it's sat since undriven.

So the error codes I have are
29D0, 29D1, 29D2(cylinder 4,5,6 combustion misfires)
2E33, 2E34, 2E35(Fuel Injector 4,5,6 activiation)
30BB(injectors 4,5,6 or DME internal fault)
29CC(combustion misfire, several cylinders)
29D9(misfire at low tank fill level)
2A2C(mixture control 2)
2AAF(Fuel pump plausibility) Now this one has popped up previously before I had any of these other issues but the car has run ok until now
2EF7(map thermostat activation) I've had this one for a very long time now and had no issues other than the engine oil taking forever to warm up.
9319(kombi fuel-level sensor left)
931A(kombi fuel-level sensor right)

So background is I have generally been running the car on low fuel for quite a while now since mpg has been absolutely terrible for a couple of years, so along with some of these faults I believe the LPFP could be at least one of the issues here due to poor mpg, 2AAF and 9319/931A and 29D9.

My other thinking is that maybe one of my lamda sensors is faulty on bank 2 due to the other codes I'm getting and some live monitoring of some values
So the values I have are

Resistor Lambda probe 2 Vk is 256 ohms
Resistor Lambda probe 2 Nk is 2560 ohms
Resistor Lambda probe Vk 1 is 256 ohms
Resistor Lambda probe Nk 1 is 256 ohms

Resistor Lambda probe 2 Nk seems like the odd one out which I believe would correlate to bank 2 so possibly the problem? My question here would be which sensor does this correlate to?

Lamda sensor before cat1 voltage 2.24 degrees CRK
Lamda sensor before cat2 voltage 3.26 degrees CRK
Lamda sensor behind cat1 voltage 0.05 degrees CRK
Lamda sensor behind cat2 voltage 0.12 degrees CRK

I am an electrician so when it uses degrees for voltage it confuses me.

These are readings from icarly and not a multimeter.

I have put some more fuel in the car since these errors have popped up and I'm still getting the same issues.

Would anyone be able to confirm my rough guesswork here? Thanks in advance for your help.

[gbalthrop]

Originally Posted by Twinsical

... error codes I have are:
29D0, 29D1, 29D2(cylinder 4,5,6 combustion misfires)
2E33, 2E34, 2E35(Fuel Injector 4,5,6 activation)
30BB(injectors 4,5,6 or DME internal fault)
29CC(combustion misfire, several cylinders) ...
2A2C(mixture control 2)
[Codes deemed INAPPLICABLE to primary issue are omitted]
Resistor Lambda probe 2 Vk is 256 ohms
Resistor Lambda probe 2 Nk is 2560 ohms...
My question here would be which sensor does this correlate to?
["2" means Bank 2 (cylinders 4,5,6); German Abbreviations: V = Vor/Before; N = Nach/After; K = Katalysator/ Catalyst]
...
Lamda sensor before cat2 voltage 3.26 degrees CRK
I am an electrician so when it uses degrees for voltage it confuses me. [It SHOULD confuse anyone who understands how an Engine or Electricity work. Degrees CRK is rotational measurement, normally Degrees Before/ After Top-Dead-Center (TDC) of Crankshaft (CRK). My take on Carly is they are basically "Computer-Hackers" who are good at hacking into the computers/ Modules in a vehicle, but know LITTLE about Automotive Engineering/ HOW a vehicle actually works. That said, it appears Carly can at least read Fault Codes in ALL Modules. Whether it has value to display (1) Freeze Frame data, or (2) Live data; or to "Activate" or "Trigger" electrical motors or solenoids (such as Injectors in YOUR case ;-), YOU will have to determine.]...

Please provide the LAST-7 Characters of your VIN, confirm you have a Multimeter, and I will provide ISTA ScreenPrints of Injector wiring for YOUR vehicle. The important codes are the three (3) Injector activation Codes, 30BB, & 2A2C (Bank 2 too LEAN). Attached are "BMW Fault Code Lookup" Fault Info Sheets for those codes. It would appear that you have a wiring or DME Fault, causing intermittent LACK of Activation of all 3 injectors on cylinders 4,5,6, all of which are served by the rear Exhaust Manifold (Bank 2). Here are Fault Info Links for FIVE (5) primary codes. My suggestion is ALWAYS check wiring/ connectors FIRST. See "Service Notes" at end of each page:
https://bmwfault.codes/XMLDiagView?d...gAMwA2ADAANAA=
https://bmwfault.codes/XMLDiagView?d...YANQA2ADAANAA=
https://bmwfault.codes/XMLDiagView?d...kAMAAxADAANAA=
https://bmwfault.codes/XMLDiagView?d...MANgA2ADAANAA=
https://bmwfault.codes/XMLDiagView?d...gANQA4ADAANAA=

While Freeze Frame data, Live data, or Activation of Injectors (attempted) MIGHT help diagnose the issue, ultimately it will come down to Multimeter Testing, for which you appear WELL-SUITED.
George

[Twinsical]

Hi George, thanks for your reply. The last 7 numbers of my VIN are P053591, I do indeed have a multimeter.

The carly is pretty handy, it can live monitor over 400 different values, just not really sure how some of these values are relevant or how to interpret them. It's good at getting me error codes and giving me a general idea of where to look. I don't believe it can do freeze frame data or activate motors or solenoids etc.

For further reference I have read that bad mosfets on the MSD80 can be a cause of the 30BB code but I have taken my DME out and checked the continuity of the mosfets and they all appear to have the correct continuity. While I am suited to testing, auto electrics is theoretically simple, but a different kettle of fish to what I'm used to but always happy to give it a go if it will save me going to a stealership.

I should also add that all of my injectors are Index 12 which I believe makes it unlikely that it would be an Injector fault.

Thanks for your help, Paul

[gbalthrop]

Originally Posted by Twinsical

... P053591... I have taken my DME out and checked the continuity of the mosfets and they all appear
to have the correct continuity...

Hi Paul,
ISTA ScreenPrints of Injector Wiring, Connector Location & Connector View are attached for your 6/2007 335i N54.
As I understand the MSD80 DME, there IS a failure mode where one Bank (e.g. 4,5,6 in your case) can fail as far
as "Activation" by DME sending "Ground Pulse" to injector. There is ALWAYS 12V+ supplied to Pin #1 of each injector
when Ignition (KL15) is ON. I would TEST wiring between DME Connector X60006 and the Respective Socket of
Injector Connector, for each cylinder: 4, 5, 6.

1) There SHOULD be battery voltage at each Socket #1, White wire, at each injector Connector: X6104, X6105 & X6106,
with Ignition ON (KL15 Active). I would DIS-connect ALL of the three injector connectors while testing, & also test for
continuity to Chassis Ground (Short) in each of the injectors, between Pin #1 & Chassis/engine Ground.

2) I would then DIS-connect X60006 connector (12-socket) at the DME & test for Continuity between each end of each
of the White wires, e.g. between X60006/4 & X6104/1, repeating for X6105/1 & X6106/1.

3) With Connectors STILL DIS-connected, I would then test for continuity to Chassis Ground (Short) in each White wire.

4) If NO "short to ground" is found in any of 3 White wires, I would then:
a) Reattach connectors;
b) Clear Codes (Ignition ON, Engine Off);
c) Attempt to "Activate" injector 4, 5 or 6, using Carly;
d) Start engine & listen for Injector Pulse/Click at 4,5,6 (if possible).

A cheap ($5 US) Mechanic's Stethoscope with bit against injector Body, or even a long-handled Screwdriver with
handle to ear can detect presence or absence of "CLICK" (compare 1,2,3).

You CAN of course test the Orange, Red & Brown Ground wires at Injectors 4, 5 & 6 similarly, for Continuity between
X60006 & Injector Connector, as well as for Short to Ground. Please let us know what you find.
George

[Twinsical]

Thanks for that. I will give that a go tomorrow. Auto wiring diagrams really confuse me. For clarification the top row (white) on the diagrams is the positive, and the Bottom row (orange, red and brown are the earths) Do the grounds go back to the DME connector or do they take the shortest route to ground?
To me the wiring diagram only makes sense if the grounds go back to the DME connector but to my limited knowledge of auto electrics I would have thought it would take the shortest route to a ground point.

So for example, X6106/1 would go back to pin 6 on the DME connector and X6106/2 would go back to pin 12 on the DME connector.

1 seems easy enough with ignition switched on, I assume with the engine off. test for 12v and then a short between pin 1 and chassis.

2 i understand

3, assuming that the grounds do go back to the DME do you mean check for a short between the 2 correlating pins on the connector?

Sorry for the stupid questions.

I have also installed ISTA myself but just realised I should probably install it on a laptop and not a desktop pc, would you be able to recommend a cable to connect the obd2 to a usb?

[gbalthrop]

Originally Posted by Twinsical

... For clarification the top row (white) on the diagrams is the positive [ONLY when Ignition ON -- note "15" = Terminal 15, Ignition, above each White wire] and the Bottom row (orange, red and brown are the earths) Do the grounds go back to the DME connector [Yes; think of Injector as a solenoid valve; 12V+ to White wires ANY time Ignition ON; DME controls AMOUNT of fuel sprayed by injectors by DURATION of Ground signal from DME to Injector pin #2 -- How LONG the injector is OPEN/Spraying] ...
To me the wiring diagram only makes sense if the grounds go back to the DME connector [That is correct -- actually, Ground Signal is sent FROM DME to Injector/Solenoid.]

So for example, X6106/1 would go back to pin 6 on the DME connector and X6106/2 would go back to pin 12 on the DME connector. [The wiring shows what you describe, but think of "Voltage Supply" from DME to injector via White wire (Ignition ON), and Ground signal, variable Duration, from DME to Injector Pin#2 to control How LONG injector sprays fuel.]...
1 seems easy enough with ignition switched on, I assume with the engine off. test for 12v and then a short between pin 1 and chassis. [Wiring Tests ONLY require Ignition ON (Engine OFF) for testing Voltage Supply via White wires. Otherwise, Test for Continuity between connectors & Short to Ground with Ignition OFF & DIS-Connected connectors at Injectors 4,5,6, AND at X60006]...
3 ... do you mean check for a short between the 2 correlating pins on the connector? [Short means "Short-circuit to Chassis Ground". That is when there is Continuity (near-zero Ohms resistance) between one end of wire (both Connectors disconnected) & Chassis Ground. Select Ohms resistance (Ω symbol), a "Mid-Range" such as 2,000 Ohms, Touch Meter Probes together to see Near-Zero Ohms reading when probes touch & "1" or Infinite Resistance (Open-circuit) with Probes NOT touching.
Then Put Red Meter Probe on ONE end of wire to be tested for "Short", and Black Meter Probe on Chassis/ engine Ground. Meter should read "1"/ Open Circuit, & NOT 0 Ohms which would indicate Short/ Connectivity to Chassis Ground.]
[COLOR="red"]Automotive Electrical Testing takes Repetition & Thought. Just take your time, experiment, think, Ask Questions. Even the guys who do this for a living make mistakes if they DON'T.

I have also installed ISTA myself but just realised I should probably install it on a laptop and not a desktop pc, would you be able to recommend a cable to connect the obd2 to a usb?

You can PROBABLY get a "K+DCAN Cable" on Amazon that will work, for ~ $30. I personally have used BimmerGeeks Pro Cable ($50) for 7 years with NO complaints:
https://www.bimmergeeks.net/product-...eeks-pro-cable

If you have ISTA installed on desktop computer, you can use that for "Shop Manual" or reference to documents such as wiring diagrams or repair procedures. See attached pdf's:
a) ISTA as Shop Manual;
b) Fault Memory & Test Plan (diagnostics using Laptop).

It takes time & THOUGHT, but you can do it.
George

[Twinsical]

gonna have to do this tomorrow, the probes in my fluke tester wont fit haha. getting a new one tomorrow.

[Twinsical]

So from testing, i had 0 to very little voltage coming from pin 1 on injectors 4,5,6 and even on injector 1 while the ignition was on which I tested to make sure I wasn't going mad.

I had perfect continuity on all 3 injectors both pin 1 and 2.

I had no shorts to ground from Pin 1 on any of the injectors.

[gbalthrop]

Originally Posted by Twinsical

So from testing, i had 0 to very little voltage coming from pin 1 on injectors 4,5,6 and even on injector 1 while the ignition was on which I tested to make sure I wasn't going mad. [ If engine is running on ~ 3 cylinders (VERY Rough, but runs) there HAS to be battery voltage (Ignition ON & X60006 CONNECTEd) on at least TWO of the 6 White wires. Please RE-TEST & post exact meter Voltage Values for each cylinder, checking ALL 6.]
I had perfect continuity on all 3 injectors both pin 1 and 2. [I presume that means Continuity in White wires between e.g. X60006/4 & X6104/1, and similar continuity between respective pins of X60006 & X6104-5-6/2, Orange - Red - Brown wires? Continuity test is with BOTH connectors disconnected.]
I had no shorts to ground from Pin 1 on any of the injectors.

Sorry to be "Wordy", but NOT taking the time to be SURE I'm Understanding your tests & results causes false ASSumptions.

After again reviewing the ISTA diagrams attached to Post #4, Please REPEAT the Voltage Measurements at Socket #1, White Wire of ALL Injector connectors, providing the exact Voltage Readout for EACH, Cylinder 1,2,3,4,5,6.

Those Voltage measurements should be with (a) ALL Injector 2-pin connectors DIS-connected, (b) DME Connector X60006 Connected, & (c) Ignition ON.

I do NOT have any information on the internal circuitry of the DME, Module 6, MOSFETs & such. However, if you can determine WHICH injectors have White Wire Voltage & which do NOT, a Module repair specialist SHOULD be able to opine on ~ Repair. All we can do WITHOUT that expert opinion is eliminate wiring as cause of fault, and make sure Test Methods were correct.
George

[Twinsical]

So here are my voltage tests with 1 probe on Pin 1 and the other on chassis earth. with ignition on and DME connector connected and injector plugs disconnected. Idk what to tell you I'm not getting 12v on any of them and the car starts but its extremely rough.

Injector 1 - 2.2mV
Injector 2 - 2.2mV
Injector 3 - 2.1mV
Injector 4 - 2.2mV
Injector 5 - 2.0mV
Injector 6 - 2.0mV

End to end continuity for Pins 1 and 2 are all good from the DME connector and the injector connectors on the wiring and there are no shorts to earth from Pin 1.

Multimeter has been tested against actual battery source to ensure it is actually working properly.

Are you sure there should be 12v at the injector with only the ignition on?

[Twinsical]

Ok, so I've finally got ISTA working and connected to the car, (that was a pain the ass)

So when it comes to triggering the injectors, I can turn off injectors 1-3 which tbh doesn't sound like it's making any difference. The ECU is unable to communicate with injectors 4-6 and it says
A communication fault occurred during activation
Incorrect State: ERROR_ECU_REQUEST_OUT_OF_RANGE

I have a ton more data obtained through ISTA,

Exhaust gas temperature is 0degrees
HPFP value 48583.04 hPa
LPFP value 5012.20 hPa
Nitrogen oxide concentration 0.00ppm
Signal, o2 sensor bank 2 before cat 3.18v
Signal, o2 sensor bank 1 before cat 1.99v
Status nitrogen oxide sensor - faulty power supply
Suplhur saturation of lean NOx cat converter is 0.00mg

additive bank 1 adaptation 0.00mg/hub
additive bank 2 adaptation 0.00mg/hub
Multiplicative bank 1 mix adaptation -5.09%
multiplicative mixture 2 adaptation 28.71%
o2 sensor control 2 is active
o2 sensor control is active
signal o2 sensor bank 2 after cat 0.16v
signal o2 sensor bank 2 before cat 3.18v
signal o2 sensor bank 1 after cat 0.76v
signal o2 sensor bank 1 before cat 2.00v

These are all live data values while at idle.

Could a bad o2 sensor be causing my ecu to shut down the whole of bank 2? Or are the o2 sensor values a result of the whole of bank 2 being shut down? I believe they should be running at the same voltage.
Also just noted that the NOx sensor appears to be bad.

I'm generally leaning towards it being a DME issue, but the lack of any failed injector or coil mosfets confuses me.

[Sgop335]

Its most likely the dme. My mosfets were fine but the power supply in the dme were an issue, had to replace dme.

[Twinsical]

Originally Posted by Sgop335

Its most likely the dme. My mosfets were fine but the power supply in the dme were an issue, had to replace dme.

What do you mean by the power supply in the DME, where is that and what does that mean. I thought the mosfets powered the injectors.

[Twinsical]

so I've done abit more testing. I tried disconnecting injectors 4-6 one by one and clearing the codes each time to see what would come back. Disconnected 4 and 5 and 29CC, 29D0, 29D1, 29D2 and 30BB all stayed. The injector activation codes have disappeared but I havn't driven the car at all, just run it at stationary. When I disconnected injector 6 at the plug all of the misfire codes have disappeared and I am only left with 30BB code.

This leads me to believe it is Injector 6 related or DME related.
I'm going to retest my mosfets and have a closer look at the DME as I don't want to go down the rabbit hole of buying injectors just yet.

I guess the next thing I should look at is coil packs and spark plugs.

[Twinsical]

Just thought I'd throw out a quick update, so I've replaced 2 out of my 3 bank 2 injectors, will replace the third one soon but I find it very unlikely that is the cause.

I have replaced all 6 spark plugs, swapped coils from bank 1 to 2 and vice versa, and still no change, same faults on bank 2.

I have sent my ECU to ECU Testing for them to come back and tell me that there are no fault codes on my ECU and it is working perfectly fine. I don't believe them but not alot I can do about it.

My main reason for this is when I use ISTA+, the program cannot communicate with injectors 4,5 and 6 when it comes to injector triggering but is fine when it comes to bank 1 injectors.

I'm left with very few options, either it's the 1 injector I havn't replaced, or I have read there could be a relay that splits the signal from the ECU to each bank of injectors. Which I am assuming is not in the ECU.

So right now, I don't have an effeing clue what is wrong with my car.

[swellengear]

I had the same issue. Mosfets tested fine, but the problem persisted. I sent it off to an ECU company, who promptly returned it to me, saying it was fine. I wasn't. I sent it back to them along with my key and CAS module. They then hooked it up to a donor car, and immediately got the faults. It turned out to be a bad solder joint within the DME. (on the board below the one with the mosfets on it)

[Twinsical]

Hello chaps, so a final update for you all, after sending my ecu off to ecu testing and them returning it to me saying my ECU was fine. I went a step further and had my ecu cloned, to another MSD80, thought about going MSD81 route but decided against it in the end.

Just put it in the car and the 30BB code has gone and is no longer misfiring. I havn't driven it yet but gave it a few revs and everything appears to be hunky dory.

So it turns out that even if your mosfets are fine, it can still be your ECU causing the problem. While the car was out of action I also took the time to investigate my 2EF7(map thermostat activation) code and found the connector was completely severed from the cable so that explains that one too!

All in all I don't recommend sending your ecu to ecu testing if your mosfets are fine, as I'm fairly sure that that is all they will check. Meanwhile sending it back with a whole load of extra sealant that made it an absolute PITA to take apart again.

[Sgop335]

Post 12

[Moose06]

Originally Posted by gbalthrop

You can PROBABLY get a "K+DCAN Cable" on Amazon that will work, for ~ $30. I personally have used BimmerGeeks Pro Cable ($50) for 7 years with NO complaints:
https://www.bimmergeeks.net/product-...eeks-pro-cable

If you have ISTA installed on desktop computer, you can use that for "Shop Manual" or reference to documents such as wiring diagrams or repair procedures. See attached pdf's:
a) ISTA as Shop Manual;
b) Fault Memory & Test Plan (diagnostics using Laptop).

It takes time & THOUGHT, but you can do it.
George

Holy smokes I just started exploring this wonderful asset that I've had an account created on for probably 8 years and two E90 vehicles but never have taken the time
to absorb any of it because it's something that's foreign to me. Have extremely limited DIY skills and just inherently not mechanically inclined which to those who are it's wild how useful those skills are in every corner of life. As I've just glossed over this interaction I feel like maybe this is string theory not a guide to what's causing misfires in 3 cylinders Amazing how it seems that this could most lily be explained in caveman to make sense and come up with solutions yet also have the intricacy that demands the attention of a couple Phds that put some real deep forward thinking into every step of the solution possibilities..