BMW 7 Series Won't Start: Bad Park Lock Mystery Fixed

Hey there! I had a similar problem with my 2010 BMW 5 series (coming from someone with some experience working on cars). The symptoms were nearly identical to what you're describing with my old 5 series, transmission issues, check engine light, the whole deal. Took it to my regular workshop and they diagnosed a defective control unit. The repair wasn't cheap, set me back about 1000 Euro, but it fixed all those transmission gremlins. I also looked at the 6 series from that generation, and they had similar issues. Before I can give you more specific advice, could you share: Current mileage? Any previous transmission repairs? Which specific error codes you're getting? This info would help determine if you're dealing with the same issue I had. Don't wait too long though, transmission problems tend to get worse (and more expensive) if you keep driving with them.

Thanks for sharing your experience! My 7er currently has 151148 KM and just had its regular service done last month. Getting P0700 and P0705 codes. The transmission issue started suddenly while parked, no previous repairs on the transmission system. Those repair costs you mentioned sound about right from what I've researched. Did you notice any weird vibrations or delays before your control unit completely failed? Just trying to figure out if I'm heading down the same path with my car before taking it to the shop.

Hey again! Yes, those codes (P0700 and P0705) are exactly what I got with my 5 series before the control unit went completely bad. And yes, I definitely noticed some warning signs before the full failure. About 2-3 weeks before it got really bad, I started getting these slight jerks when shifting from Park to Drive, and there was this weird split-second delay when changing gears. In my case, I actually ignored those initial symptoms (big mistake) and kept driving until one morning the car just wouldn't start normally. Looking at your mileage, it's pretty similar to what mine had when the issue came up (mine was around 160,000 KM). Since you mentioned it started suddenly while parked, that's another telling sign it's probably the control unit. My mechanic explained that these units tend to fail this way in these models, they either give you some warning signs or just go out suddenly. Just a heads up, when they replaced my control unit, they also had to reprogram it to sync with the car's computer system. Make sure wherever you take it can handle the BMW-specific programming. The repair took about two days total in my case. Let me know how it goes, sounds like you're dealing with the exact same issue I had.

Thanks so much for all that detailed info, it's super helpful! Those symptoms you described are spot-on with what I'm experiencing. The jerking from Park to Drive and that gear change delay, I've noticed both but didn't connect the dots until now. Really good to know about the programming requirement too, definitely going to make sure the shop can handle that before I take it in. Think I'll stop driving it for now and get it looked at this week. Don't want to risk making it worse like you mentioned. Will probably need to brace myself for that repair bill, but at least I know what I'm likely dealing with. Really appreciate you sharing your experience, saved me a lot of worry about what might be wrong. I'll update you once I get it sorted out!