[alex_k_145]

I am facing an issue with my oil level sensor reading inactive and my oil CBS can not be reset via the dash or a computer at my mechanics shop. We also tried to adjust the oil change # on the computer but had no success as it read 0. The oil level sensor and the wiring are okay and were verified using electrical testing equipment. This leads me to believe that this is caused by a CBS system error in the car.
My question is how would I code out the oil CBS in the system or reset it through tool 32 to be able to read my oil level again?

[ptpending]

the oil sensor, alternator and ibs sensor and dme is hanging on one simple BSD bus
if one of this devices have short circuit on this bus or something like that, it's BSD transceiver can fail and disturb communication with all other devices

[alex_k_145]

Thanks! Can this issue arise if the alternator and water pump were recently changed?

[alex_k_145]

My battery was also changed recently so do you think this could cause the problem?

[ptpending]

Originally Posted by alex_k_145

Thanks! Can this issue arise if the alternator and water pump were recently changed?

oh forgot that water pump is also on bsd
yes, you need either try to read codes to understand what from these devices failed(lost communication) first
or use oscillograph to check the BSD signal

[alex_k_145]

thanks appreciate the help lucky for me I'm a mechatronics engineer and have an oscilloscope to check the data. Do you maybe know where I can get a baseline reading or an image of what the signal should look like on the scope?

[ptpending]

Originally Posted by alex_k_145

thanks appreciate the help lucky for me I'm a mechatronics engineer and have an oscilloscope to check the data. Do you maybe know where I can get a baseline reading or an image of what the signal should look like on the scope?

in ISTA (bmw software)
it is very simple 1-wire LIN bus

[alex_k_145]

thanks for the info i will run that

[alex_k_145]

Well, I have had some time to sort through the whole BSD system in the car and test every single wire for each component to ensure no faults. However, after unplugging everything and checking for shots on the BSD bus there were no issues with the hardware. and all the components are new so they don't seem to be the fault. I am wondering if there is anything else I can check before I open up the DME. Also is there even a way to fix the bsd line in the DME if that is the problem?

[spazzz]

Do you have over 300,000 km on it. If you do, have you read this?

https://www.e90post.com/forums/showthread.php?t=926864

[alex_k_145]

Unfortunately this is not the issue I wish it was though

[alex_k_145]

Issue was solved with new ecu. Bsd bus failure was the problem. This damaged my alternator and water pump because they rand in fail safe state. Those parts were replaced under warranty. With the new ecu the car work absolutely perfectly.