Thanks for chiming in. I’m really sorry for not being more specific, but here’s the whole story: Around a month ago, I noticed some dash lights while driving. If I recall, it was the 4x4 indicator. It drove fine and everything, and eventually the light disappeared. Last week, I had to move the x5 out of the garage and when I started it, I noticed the brake pedal fell all the way to the floor. After shutting it off and back on, the pedal stiffened up again so I was able to move the suv. However, the pedal wasn’t the same as it would still slowly move downwards if I kept my foot depressed on it. Then the following weekend, I decided to replace the master cylinder and I bled all 4 wheels after. I’ve even used foxwell to bleed the abs too. I took it out the next day and that’s when I got stranded on the bridge with 4x4 and dtc on the display screen. I’m now wondering if it’s the brake booster contaminated by oil inside the vacuum line. I know years ago there was a recall about this, but my door jam sticker has the code punched out, so it’s been addressed before by bmw. There’s just 62k miles. I also noticed when idling in park, the brake pedal does gets stiffer when I depress it a few times. However, when I shift it to D, it feels normal again.