BMW 5 Series Brake Warning Light Nightmare

Had the same issues with my 2012 BMW ActiveHybrid 7. The symptoms you're describing match exactly what I experienced, spongy brake pedal, warning lights festival on the dash. Turned out it was an undervoltage problem with the battery system that was affecting the brake control module. The hybrid system's integration with the regenerative braking was messing things up. When I got it checked, they had to recalibrate the brake control unit and replace the auxiliary battery. It's definitely not just worn brake pads, this is more serious because it involves the hybrid system's electronics. The warning lights coming on together is a big red flag. My car was in the shop for three days while they diagnosed and fixed everything. Don't put this off, it's a safety issue that needs proper diagnosis. While brakes worked, they weren't providing full power, which isn't something you want to risk. Make sure you find a mechanic who's specifically experienced with BMW hybrid systems. Just for context, this wasn't a simple fix-it-yourself job. Needed specialized diagnostic equipment and BMW-specific knowledge.

Hey, thanks for sharing your experience! It helps knowing someone else went through the exact same thing. I took your advice and had it checked at a specialist, definitely the right call. The hybrid battery was indeed causing problems with the brake system, just like you said. Quick question, do you remember roughly how much the repairs set you back? Also, has everything been running smoothly since the fix, or have you noticed any other quirks?

Hey there! Happy to help with the brake situation, glad you got it sorted out at a specialist. The total cost was 240 € for fixing the undervoltage issue, and honestly, it was worth every penny. Since getting it fixed, my BMW ActiveHybrid 7 has been running like a dream, no more brake problems or warning lights whatsoever. The worn brakes were completely sorted out during the repair too, so that's a relief. The pedal feel is back to normal, and the regenerative braking system is working perfectly with the hybrid system now. I've put about 15,000 km on it since the repair with zero issues. The only quirk I've noticed is that the battery seems to take a bit longer to charge in cold weather, but that's totally normal for hybrids. The braking system has remained rock solid though. Just make sure you keep an eye on the battery voltage readings during your regular maintenance checks, it's a good way to catch any potential issues before they turn into bigger problems. Let me know if you notice anything else unusual!

Thanks everyone for your helpful feedback! I wanted to update you all on what happened. Finally got my BMW checked at a different mechanic, a certified hybrid specialist this time. What a difference! The mechanic found the problem right away. Just like you mentioned, it was related to the hybrid system's battery affecting the brake module. The repair took two days and cost around 300. They had to recalibrate the entire braking system and fix some electrical connections. The best part? No more warning lights, and the brake pedal feels normal again! The mechanic also gave me a full rundown of what to watch out for in the future. They said regular system checks are crucial for hybrid vehicles. Really glad I didn't ignore those warning signs. The peace of mind was worth every penny spent at the specialist. The car drives so much better now, it's like having a new vehicle! Thanks again for pushing me to get it properly checked out.