BMW Z3 Power Seat Mystery: Driver Profiles Not Working

I had a similar issue with my 2003 BMW Z4 last year. The power seat system started acting up, and it turned out to be more than just a seat problem. The technician found that my battery was severely discharged, which was causing electrical system malfunctions across the car. The seats wouldn't move until the engine was fully running because the battery couldn't provide enough power during low-voltage situations. In my case, they had to replace the battery and also found a faulty voltage regulator that was draining the battery even when the car was off. The alternator was tested and thankfully was fine. It was quite a serious issue since a bad battery can cause various electronic failures in BMWs. The memory seats use quite a bit of power, and they're usually the first to show symptoms when there's a power supply problem. After the fix, all electrical systems went back to normal, including the seat memory functions. I'd suggest getting the battery and charging system checked before diving into seat motor repairs. These electrical gremlins can be tricky, but usually, there's a logical explanation behind them.

Thanks for sharing your experience! That's really helpful. My issue sounds very similar to what you encountered. I was actually wondering, do you remember roughly how much you ended up paying for the whole fix? And has everything been working properly since then, or have you noticed any other electrical quirks? Just trying to get an idea of what I might be looking at cost-wise and if I should expect any follow-up issues. These electrical problems can be such a pain with these cars!

Hey again! Happy to give you an update on my Z4 situation. I ended up paying 290€ for the battery replacement and diagnostic work, and I'm glad to report it was money well spent. The passenger seat electrical system has been working perfectly since the fix, no more waiting for the engine to start before adjusting the seats! It's been over a year now, and I haven't had any other electrical issues pop up. The memory settings work right away when I hit the ignition, and all the other electrical bits are behaving just as they should. I was worried at first that other problems might surface, but honestly, replacing that drained battery sorted everything out. Just one tip from my experience, if you do get it fixed, make sure they do a full charging system check while they're at it. It's worth knowing that everything else is working properly to prevent any repeat issues. These older BMWs can be finicky with their electronics, but once you get them sorted, they're usually pretty reliable.

Thanks for all the details! I finally bit the bullet and took my Z3 to the mechanic last week. Turns out you were spot on, it was mainly an electrical issue. My voltage regulator was shot, and the battery was barely holding a charge. Had both replaced, plus they cleaned up some corroded connections they found while poking around. Total bill came to about €400, which wasn't as bad as I'd feared. The mechanic was great this time, showed me everything they found and explained why the seats were acting up. Been driving it for a few days now, and what a difference! The seats adjust instantly when I hit the power button, and all the memory settings work perfectly. No more waiting for the engine to warm up. Really appreciate you sharing your experience, helped me go in knowing what to look for and gave me confidence to push for a thorough electrical check. These old BMWs sure can be tricky, but at least this problem's sorted now!