According to our non-Euro car shop, my wife's '06 4.8L X5 is showing the following codes:

2B70 - DISA
2B71 - Failure DISA
2B72 - DISA Temp Warning

The code descriptions come from an online search, not the shop.

The plot thickens when I tried to source a replacement DISA valve - evidently it's a 6 cylinder only part and not found on BMW's V8's.

Thoughts on what might be wrong and how I can run this down? We are remote from a dealer - about 3-1/2 hour drive away - so would like to consider that the option of last resort.

Thank you.