A friend has an R56 that's indicating an airbag malfunction. He asked for a bit of assistance since I generally work on my own vehicles, but I could use a bit of guidance.

Originally he was told by a local shop that it was generating error code 93D7. We removed the console and checked for obvious moisture damage without finding any. At that point, we installed a used airbag control module, but it's still showing a fault (solid airbag light on the gauge unit in the center).

I pointed him to the USB to OBD2 adapter cable and these instructions for setting up the BMW Standard Tools. With that installed, we were able to connect his laptop to the car reset any existing airbag fault codes. The light did not clear after that, so we retrieved them again in INPA. All modules appear to be showing clear except MRS. It's indicating seven issues:
93C0 E4
93A9 E8
9418 E0
9417 E0
9419 E0
941A E0
93AA E8

Can someone help steer me in the right direction for diagnosing/repairing the underlying cause?
Thanks!

 

You need to recode the new MRS. This can be done easily with NCSExpert, which is part of BMW standard tools.
Basically, read the VO and code the MRS with a blank MAN file. There should be some tutorials online.

 

Great, thanks! I'll dig around for a tutorial.

 

If I'm understanding the process correctly (trying to get my head wrapped around it before I go by to look at it again)...

Connect the laptop the car and launch the NCSExpert software
Enable expert mode and choose the chassis type
Use 'process ecu' to get a list of the available subsystems and select MRS
Use the 'choose job' function to click the correct button to read the existing MRS data as a text file that gets deposited in the NCSExpert software folder
Use a text editor to make the appropriate changes to the text file (I'm not clear on what those are yet), then save that file with a .man extension
Upload the modified file to the car using the software.

Is that approximately it? Also - do you know what change needs to be made to the file?

Thanks for everything.

 

That process is if you'd like to make changes to the factory default coding. What you want to do is revert your module back to factory defaults.
Check out this link. It's a little wordy but it explains the "whys" of each of the steps. Scroll down to the section "To load up the ORIGINAL factory defaults if you mess up." and follow those instructions.
https://www.bimmerforums.com/forum/s...ith-NCS-Expert

 

I have replaced the steering wheel airbag, Ebay- junkyard unit- I have sent off my airbag module, to a local company that does module resets and reinstalled it.
I have repaired all the rest of the front end damage.
After using my Foxwell 625E scan tool, I have reset all the fault codes from the accident and driving it home after. (about 2 blocks)
I still have an airbag light and a fault code for the ACS/MRS: Belt tensioner, Driver. Code:93A9
What info I can find, points to the drivers seat belt. Does this mean I need to replace the Seat belt assembly or the latching mechanism?
the Drivers seat belt seems to function normally, it isn't locked in place.
Is this a connector issue? Can it be bypassed?

 

Hello,
Yes, I replaced the seat belt latching mechanism, part that is attached to the seat. The seat belt latching mechanism has connectors that are connected to the internal switch that latches on, basically telling the ECM that the airbag has been deployed.
I ordered the seat belt latching mechanism from Ebay (its the part you click the belt into, and has the button you press to release the seat belt.)
I did have to disconnect the connectors for the heated seat and the seat belt and remove the seat to replace the seat belt latching mechanism
So i recommend disconnecting the battery before removing any of the connectors.


Good Luck.

Roger