BMW XM Multiple Warning Lights & Brake System Issues

I have some experience with BMW maintenance, and I dealt with a similar situation on my 2021 BMW X6. I initially thought it was brake-related too, but it turned out to be an undervoltage issue affecting multiple systems. The symptoms were exactly like yours, weird brake pedal feel and a Christmas tree of warning lights (ABS, ESP, brake). My local workshop diagnosed it and found the voltage issue was messing with the brake control modules. The fix cost me about 240 Euro, and they had it sorted in about a day. Before that, I actually owned an X5 too, and these electrical gremlins can be tricky with modern BMWs. Could you share: How long have these symptoms been present? Have you noticed any battery-related issues, like slow starts? Are the warning lights constant or intermittent? This info would help me better understand if you're facing the same issue I had.

Thanks for sharing your X6 experience! My XM has been showing these symptoms for about 3 days now. The warning lights stay on constantly once they appear. I've done my last service about 2 months ago at 185327 KM, and everything was fine until now. Haven't noticed any battery issues, starts up perfectly fine every time. The brake pedal feels spongy specifically when coming to a stop, which made me think it might be different from an electrical issue. This is actually quite concerning since the car is still relatively new. I might have to get it checked by a BMW specialist soon if it persists. Did your voltage issue also cause spongy brake feel, or was it more about the warning lights?

Yeah, I totally get your concern about the spongy brake feel. When I had my X6 issue, the brake pedal wasn't really spongy, it was more like inconsistent feedback. That's actually an interesting detail you've mentioned there, and it makes me think your case might be different from what I experienced. Given what you're describing, especially that spongy feel when stopping, I'm starting to think it could be a hydraulic issue in your brake system rather than the electrical problem I had. These new BMWs have pretty complex brake-by-wire systems, and when there's air in the lines or a potential master cylinder issue, it can cause exactly what you're experiencing. I actually had a somewhat similar spongy brake issue on my previous X5, and it turned out to be air in the brake lines. That was a completely different fix from my X6's voltage problem, cost a bit more too, around 400 Euro for a full brake fluid flush and system bleeding. Since your XM is still pretty new, I'd definitely get it to a BMW specialist ASAP. Could be covered under warranty too. Better safe than sorry when it comes to brakes, you know? Keep us posted on what they find, I'm actually really curious to know if it's similar to any of my past experiences or something completely different.

Thanks for the detailed follow-up! You've actually made me feel a bit better about taking it to the specialist. The difference you described between spongy and inconsistent feedback makes a lot of sense. I just called the BMW service center and got an appointment for tomorrow morning. You're right about the warranty, they confirmed it should be covered since the car's only 8 months old. I'm really hoping it's just air in the brake lines like your X5 had, though the multiple warning lights still have me a bit worried. I'll definitely update this thread once I get the diagnosis. Really appreciate you sharing both your X6 and X5 experiences, it's helped me better understand what might be going on. These modern BMWs sure are complex machines! At least the car's still driving well enough to get to the service center safely.