BMW Z3 Seat Massage System Malfunction, Troubleshooting Help

Hi there! I've got some experience with BMWs, I faced a similar issue with my 2004 BMW Z4, and I also own an X3. Yeah, that massage seat problem can be super annoying! Had the same thing happen to me. Turned out the connection cables behind the switch were loose, and some connectors were corroded. My mechanic had to replace the wiring harness and clean up the connection points. The whole thing cost me around 95 Euro, but it's been working perfectly since then. Before I can give you more specific advice, could you share: Have you noticed any other electrical issues in the seat? Does the problem happen all the time or just occasionally? Can you hear any clicking sound when you try to operate the switch?

Thanks for the detailed response! My Z3 has 137641 KM on the clock and had its latest service about 2 months ago. The clicking sound is definitely there when I press the switch, and it's been happening consistently for the past week or so. No other electrical issues with the seat that I've noticed, everything else works fine, including the regular seat adjustments. The problem is there all the time now, though it started intermittently at first. Your wiring harness solution sounds promising, I'll have my mechanic take a look at the connections. Really hoping it's just a wiring issue and not something more serious!

Hey again! Thanks for providing those extra details about your Z3. The symptoms you're describing sound exactly like what I experienced, especially that clicking sound and how it started intermittently before becoming constant. That's almost identical to what happened with my Z4! Since you mentioned it's been consistent for a week and started after working fine, I'm even more convinced it's the wiring issue I dealt with. The clicking sound with no function is typically a telltale sign of poor electrical connection. When my mechanic opened up the seat on my Z4, you could actually see where the wires had started to wear down from all the seat movements over time. Since your car's just had a service, maybe they moved something around that made the wiring issue worse? Mine started acting up after a deep clean when the seat was moved back and forth a lot. Quick tip from my experience, while you're waiting to get it fixed, try not to keep pressing the switch too much. I made that mistake and it ended up causing more strain on the already damaged wiring. Better to wait until it's properly fixed. Let me know how it goes with your mechanic! I'm pretty confident it'll be the same issue as mine, especially given all these matching symptoms.

Thanks so much for all this great advice! I really appreciate you sharing your experience and the tip about not pressing the switch too much, I've definitely been guilty of repeatedly trying it, so I'll stop doing that right away. You might be onto something about the recent service causing the issue. They did have to move the seat quite a bit while working on something else, so that could've disturbed some already worn wiring. It makes perfect sense now that you mention it. I've already called my mechanic and booked an appointment for next week. I showed him your comments about the wiring harness and connectors, and he agrees it sounds like the most likely culprit. He's ordered the parts just in case, so hopefully it'll be a straightforward fix like yours was. Really glad I asked here, you've saved me a lot of worry about it being something more serious. I'll update you once it's fixed! Thanks again for all your help!