[lomon98]

Hi,

I've got a e92 335i n55 (108k miles) and today I tried reading my oil level and to my surprise iDrive said "Measurement inactive. Service interval adjusted. Have the system checked during next oil service". Naturally I don't want to wait a few months for my next oil change as I like keeping track of my oil level ( I put a liter 2 weeks ago as it has consumed it all in less than a year ). My DME codes are:

3446 - BSD, message; oil condition sensor: Missing.
38A4 - BSD, message; intelligent battery sensor (IBS): Missing.

I've noticed in other forums that the 38A4 one is just a consequence of the other one so I don't think there is a problem with the IBS sensor (could be wrong, just guessing). I've also seen people get other BSD related codes along with these ones so I am not sure what is triggering mine exactly. Any ideas?

Thanks!

[lomon98]

Bump

[lomon98]

I decided to take the car to the mechanic to do an oil change as it is due soon anyway... will bring a new oil level sensor. I've seen the bmw one is a bit pricey compared to others such as this RIDEX one. Is it worth it to get the OEM one?

Thanks!

[lomon98]

Update: just did the oil change and swapped the sensor with the ridex one from autodoc. Problem is still there and I am still getting the same codes... I don't know what to do anynmore

[lomon98]

Originally Posted by lomon98

Update: just did the oil change and swapped the sensor with the ridex one from autodoc. Problem is still there and I am still getting the same codes... I don't know what to do anynmore

Also just mention that the sensor was receiving power so in theory there is nothing wrong with the electric line/harness. I am thinking it could be software / ECU related maybe.

[gbalthrop]

Originally Posted by lomon98

... e92 335i n55... DME codes are:
3446 - BSD, message; oil condition sensor: Missing.
38A4 - BSD, message; intelligent battery sensor (IBS): Missing.

Fault Codes indicate a Signal is "Missing", Out of range, etc. Fault Codes do NOT mean "Replace Part X".

My interpretation of your two-reported Faults is that the DME is NOT able to communicate with the OZS (Oil Condition
Sensor) via the BSD Bus (Violet wire as shown on attached ISTA ScreenPrint). ALWAYS check wiring BEFORE replacing
component, as suggested in "Service Plan" in Fault Info sheet linked below. If you would like test suggestions using
$10 US/ 10 Quid (Amazon UK) Multimeter, please advise & provide Last-7 Characters of VIN.

Generally: you want to inspect each of the Pins & Sockets, & the Violet wire where it attaches at X62540/1 and ALSO at
X60002/43. Then TEST wire for continuity between X62540/1 & X60002/43. ALSO Test for "Short" to Chassis Ground.

Here are "BMW Fault Code Lookup" definitions of those two codes, with Fault Info Sheet for each linked below definition:
3446 | BSD, message; oil condition sensor: Missing | mevd176k | Engine electronics
https://bmwfault.codes/XMLDiagView?d...kAMAAxADAANAA=

38A4 | BSD, message; intelligent battery sensor (IBS): Missing | mevd176k | Engine electronics
https://bmwfault.codes/XMLDiagView?d...kAMAAxADAANAA=

Attached are ISTA ScreenPrints of the Violet BSD Interface wire, with Connector Location & Connector View (for Pin# ID)
of the Connectors at the OZS & X60002 at the DME beneath the Intake Manifold.
George

[lomon98]

Originally Posted by gbalthrop

Fault Codes indicate a Signal is "Missing", Out of range, etc. Fault Codes do NOT mean "Replace Part X".

My interpretation of your two-reported Faults is that the DME is NOT able to communicate with the OZS (Oil Condition
Sensor) via the BSD Bus (Violet wire as shown on attached ISTA ScreenPrint). ALWAYS check wiring BEFORE replacing
component, as suggested in "Service Plan" in Fault Info sheet linked below. If you would like test suggestions using
$10 US/ 10 Quid (Amazon UK) Multimeter, please advise & provide Last-7 Characters of VIN.

Generally: you want to inspect each of the Pins & Sockets, & the Violet wire where it attaches at X62540/1 and ALSO at
X60002/43. Then TEST wire for continuity between X62540/1 & X60002/43. ALSO Test for "Short" to Chassis Ground.

Here are "BMW Fault Code Lookup" definitions of those two codes, with Fault Info Sheet for each linked below definition:
3446 | BSD, message; oil condition sensor: Missing | mevd176k | Engine electronics
https://bmwfault.codes/XMLDiagView?d...kAMAAxADAANAA=

38A4 | BSD, message; intelligent battery sensor (IBS): Missing | mevd176k | Engine electronics
https://bmwfault.codes/XMLDiagView?d...kAMAAxADAANAA=

Attached are ISTA ScreenPrints of the Violet BSD Interface wire, with Connector Location & Connector View (for Pin# ID)
of the Connectors at the OZS & X60002 at the DME beneath the Intake Manifold.
George

wow first of all apologies for the late reply, and thanks a lot for the extensive explanation, although I feel I need a degree in BMW electronics . I any case I will get a voltmeter and try to look where is the problematic sensor/wire as that is the only solution I can think of atm

[lomon98]

Hi, I want to try disconnecting the IBS sensor to see if I am able to get a read of my oil level in case the IBS sensor is the one causing the problem (I hope this makes sense). Does anyone know where is the blue plug on the lci e92 models? I cannot locate the one Ive seen in the non lci ones (lots of pics and videos of that one out there but non of the lci…)

Thanks!

[TheMidnightNarwhal]

Originally Posted by lomon98

Hi, I want to try disconnecting the IBS sensor to see if I am able to get a read of my oil level in case the IBS sensor is the one causing the problem (I hope this makes sense). Does anyone know where is the blue plug on the lci e92 models? I cannot locate the one Ive seen in the non lci ones (lots of pics and videos of that one out there but non of the lci…)

Thanks!

I'm not sure but on my E92 LCI the connector going into the IBS on the negative side is black and just unplugs there.

[lomon98]

So today I managed to disconnect the IBS terminal from the negative terminal of the battery and still got the same codes as before. I am now wondering whether this could be the connection to the sensor (X62540 in the pictures above) that somehow got damaged the last time I took the car to the mechanic (catless dp fitting)… will try to give it a look but I am beginning to lose patience so maybe I will take it back to an indy or the bmw dealer

[lookalikehuuh]

Also, keep in mind that bad signals from other BSD devices like the Alternator or the water pump can also cause other devices to lose signal or stop communicating.

as a test you can unplug the BSD bug plug from the alternator and see if the sensor starts working again. If that doesn't work then you can try it with the water pump.

I once replaced my alternator with an Autozone alternator and it caused issues with everything on the BSD bus.

[Xramses]

Hi, got the save failures:
38A4, 3847, 378F, 3446

First it began with too often running electric water pump even when motor cold and I unlocked the car with cold motor.

Then, the oil level inactivity. I bought and changed after 2,5k kilometers oil change a VEMO sensor. Same oil refill as oil change was not long ago, with additional 0,5 liters to the other quantity.

After 5 minutes driving and visible oil level, same level measurement inactivity. then after 40 driving I stopped and went under car and with no motor running I unplugged and replugged the cable of the oil level sensor. For some minutes after that the level measurement worked again. Then back to inactivity.

Suspiciuos is for me the Alternator/Generator and/or IBS. Where is the IBS located? just at the ground Battery cable? Part 12427603567?

I wanna check the sensors cables (oil level sensor & water pump) for potential damage and consider to change alternator and IBS.

[lomon98]

Hello everyone,

So just to provide an update I checked the wires and one of them was measuring 0.5 V (and when fed an impulse switched to 0V), ground and live seemed fine so wiring seems to be okay?

Now my question is whether I swapped the oem sensor for a non compatible aftermarket sensor (Ridex one from Autodock) hence if my old oem sensor was faulty maybe the one I replaced it with is not compatible and I disregarded the sensor problem too quickly.

The other possibility is that the DME circuit for the oil condition sensor is been shorted somehow and now needs to be repaired.

Any thoughts are welcome. Also prayers 😂

Cheers

[lomon98]

Hello again,

Another update from today. Despite not receving any Coolant Pump related codes the mechanic from the BMW dealer advised a faulty signal from the coolant pump was the root of the problem. Very weird. Anyone knows if I should I replace the coolant pump or is it possible to fix the circuit somehow?

Cheers!

[StradaRedlands]

I hate the BSD so much... we threw a oil level sensor, water pump, alternator pulley/bearing at the problem before it was finally diagnosed as alternator cause. PO put a cheap aftermarket in and it was causing all the problems. INCREDIBLY frustrating and expensive experience. Good luck with your system, and if the wiring & plugs are all good, double check the alternator and make sure it is the right kind in there.

[lomon98]

Indeed! I am gonna leave the technician comments here for completness.


Technician Comment:
I connected charger and carried out a survey. faults stored for oil level sensor and for the ibs sensor of the battery, carried out test plan which recommended me to carry out wire testing on the BSD lines.

I carried out wire testing at the: alternator, coolant pump and the ibs. i got all the results i was expecting. i then attempted to carry out the oil level test with everything unplugged apart from the oil level sensor. which when the faults were deleted worked. I then sequentially went and plugged in and re read the oil level till I plug something in that would stop this from working, when i got to the coolant pump I couldn't measurer the oil level, i then unplugged it and deleted the fault memory. i was then able to measure it I re did this for the other components but the fault only returned when the coolant pump was plugged in. ive since gone back to the coolant plug and carried out full wire testing to make sure its not a wiring issue and only a component issue, the wiring was indeed okay.

Hope this helps!

TLDR: dont trust the codes you get, if you get the two codes for IBS and oil level sensor check all of the components who they share signal with! And dont replace before doing thosd checks!