Using BMWhat I managed to see that I have the error code 2B71 "Failure DISA / intake manifold pressure sensor / DME, internal error: accelerator monitoring module." I can't seem to find much information regarding this error how to work on or troubleshoot on the 545. Seems to be a common enough issue on the 6 cylinders but when it comes to the 8 cylinder I feel like I'm lacking info.
Is there a way to repair or troubleshoot this piece before just buying a new one and where is it?

 

If im not mistaken DISA valve is bad. needs replacement.