BMW iX1 Brake Booster Sensor Troubles: Owner Seeks Help

I had a similar issue with my 2019 BMW i3s last year. The symptoms you're describing match exactly what I experienced, poor brake response, warning lights, and that distinct hydraulic pump noise during braking. Initially thought it was just air in the lines, but turns out the brake system wasn't bled correctly during routine maintenance. The mechanic had to completely re-bleed the brake system and recalibrate the brake pressure sensor. It was a serious safety concern that needed immediate attention. My suggestion would be to have it checked ASAP. These symptoms shouldn't be ignored, especially in an electric vehicle where brake system integration is more complex. The regenerative braking system ties into the traditional hydraulic system, so proper diagnosis is crucial. The repair took about a day at the shop, but it resolved all the issues completely.

Thanks so much for sharing your experience! What you described sounds spot on with what I'm dealing with. Good to know it might be related to improper bleeding of the brake system, that's actually a relief compared to what I was thinking. Do you remember roughly how much the repair set you back? Also, has everything been running smoothly since the fix, or have you noticed any other quirks with the braking system?

Hey again! Happy to give you an update. Since my last post, I can confirm it was exactly what I thought, the brake system wasn't bled properly. Got it sorted at the mechanic and the brake booster pressure sensor failure is completely fixed now. The whole thing only cost me 90€, which was a relief as I was expecting much worse! Everything's been running like a dream since then, no more warning lights, weird noises, or dodgy brake response. My i3s is back to its old self, and the braking feels nice and smooth again. It's been several months now and I haven't had a single issue with the braking system. Trust me, it's worth getting it checked out. The peace of mind alone is worth it, and it's way better than worrying about brake problems every time you drive. Plus, the fix was way simpler and cheaper than I initially feared!

Thanks for the follow-up! Just wanted to share that I finally took my car to a new mechanic yesterday. You were right about getting it checked, the whole experience was way better than expected. Turned out my issue was also due to improper bleeding, just like yours. The mechanic flushed the system, did a proper bleeding job, and ran some diagnostics. Everything's working perfectly now, no more weird noises or warning lights. The brakes feel responsive again, and that annoying hydraulic pump sound is gone. Best part? It only cost me around 120 bucks, which was a huge relief! Really glad I didn't put it off any longer. The repair was much simpler than I'd feared, and I'm no longer stressing about my brakes every time I drive. Thanks again for encouraging me to get it sorted, you definitely saved me from what could've become a bigger headache!