BMW X5 AC Dead & Error Codes, Heat Sensor Issue?

Hey there! I've got some experience working on BMWs (some experience, worked on a few cars). I had a similar issue with my 2001 BMW X3 last summer. The AC control unit completely died, no response, blank display, the works. Initially thought it was just a sensor like you mentioned, but after taking it to my regular workshop, they diagnosed a failed control unit. My repair bill came to around 980 Euro, which included the new control unit and labor. The mechanic mentioned these units are pretty common failure points on BMWs from that era. My 7-series from the same generation had similar issues too. Could you share more details about the error messages you're seeing? Also, does your AC make any unusual noises when you try to turn it on? This could help narrow down if you're dealing with the same problem I had. Another quick question, have you noticed any other electrical issues recently? Sometimes these problems can be related to other electrical components in the system.

Hi again! Thanks for sharing your experience. Just got my car serviced last month at 115752 KM, but this issue started popping up recently. No weird noises from the AC, it's just completely dead. The error messages are similar to what you described, and I haven't noticed any other electrical problems. I was hoping it would just be a sensor, but after reading your response, I'm getting worried it might be the control unit. Definitely not looking forward to that repair bill! Might need to start setting aside some funds just in case. Did your car show any warning signs before the control unit completely failed? Just trying to figure out if I should expect things to get worse before I can get it fixed next week.

Hey again! Yeah, looking back at your symptoms, they're pretty much identical to what I experienced with my X3. Actually, now that you mention it, I didn't get many warning signs before the complete failure. It was pretty much working fine one day and dead the next. Though thinking about it, I remember the temperature control was a bit inconsistent for maybe a week before it died, like it wouldn't maintain the set temperature properly, but I didn't think much of it at the time. The no-noise situation is exactly what happened with mine too. Just complete silence when trying to activate the system. This is typically what happens when the control unit fails rather than when it's just a sensor issue. When I had sensor problems in the past, the system would at least try to work, making some noise even if it wasn't functioning correctly. Since your mileage is pretty similar to what mine was when it failed (mine was around 120000 KM), I hate to say it, but I'm pretty confident you're looking at the same control unit failure. These units seem to have a lifespan of about 8-10 years before they start acting up. One piece of advice, when you get it fixed, make sure they check the entire AC system while they're at it. My mechanic found that the prolonged control unit issue had put extra stress on some other components. Better to catch any potential problems while they're already in there.

Thanks for all that detailed info, really helps to hear from someone who went through the same thing. It's pretty much confirmed my fears about the control unit, but at least now I know what I'm dealing with. Good tip about getting them to check the whole AC system too, definitely don't want any surprise issues popping up later. Guess I'll be calling my mechanic tomorrow to schedule that repair. Better to get it sorted now before summer hits and I really need that AC working. Really appreciate you taking the time to share your experience and all the details about what to expect. This definitely helps me plan for what's coming, both for the repair and my wallet! Thanks again for all your help. At least I won't be walking into the repair shop completely in the dark about what's going on!