Not sure if youve seen this:



https://ia801005.us.archive.org/11/i...0Diagnosis.pdf


Interesting stuff on busses.


And this:


https://ia801005.us.archive.org/11/i...System%203.pdf


Do keep in mind that the admonishing about how you need to replace parts as pairs, order specially coded parts, applies to BMW dealers. Others have figured out how to hack all that.