X5 35D E70, Engine Malfunction, Reduced Power, fault code p02cb

[09X5diesel]

This just happened to my wife over the weekend out in bfe 200 miles from home or a dealer... She just got done passing a bunch of cars up a hill under boost, haulin and the idrive info panel message came up Engine Malfunction, Reduced Power. She was able to gain a little more power back to get over hills putting the automatic shifter in manual mode to get home. DIY guy here before throwing a $500 bill at the dealer or more just to look at it.... took it to O'Reilly auto parts and borrowed their scanner. The code that I got was a p02cb Turbocharger/Supercharger "B" Underboost Condition. I did a search with the code on this forum site but found nothing.... looking for tech info... oh and yes after she got home, shut off the engine, let it sit for a few minutes, I got in to check it out and no messages on idrive, drove it and had full boost and drove normal... WTH!? Any techs on here know where to start to see what caused the fault code? ATT I'm letting the engine cool off before I start looking at the turbo and all its connections.

THanks for the help...

[jw0595]

Did you ever resolve this? I had an identical event this weekend on my 335d. I've just replaced the egr cooler, #2 injector and had the software updated. Finally got the CEL off but it still misses at idle and loads up if you floor it. I have a JB & Pedalbox and the trans. is flashed. I was trying to pass a couple of semis in Ocoee GA and all of a sudden things get twitchy. I stopped and tried to Google but had no coverage. When I restarted limp mode was gone. Coming up on my 2 yr anniversary with this car and it has yet to make a 200 mile trip without the CEL coming on. I could buy a decent house for what I have spent on repairs. Any help is appreciated!

[PanzerI]

Any solution for this guys; my X5 started doing this a few weeks back. Every time I floored it it would go into limp mode, I'd have to pull over, turn the car off, back on, then the error would go away. However, last night same situation, but the Check engine light is stuck on. I have these two error codes: P02CB & P323F. Any help or direction would be helpful.

[PanzerI]

Did anyone ever figure this out? My X5 only does this when I’m going up at altitude.

[jclausen]

Take the car to a good independent Bmw shop