BMW Z3 Key Symbol: Fix for Dead Start & Hall Sensor

Hey there! I had the exact same issue with my 2003 BMW Z4 last winter. Started with the key symbol on the dash, and the car wouldn't start. Initially thought it was just a dead key battery, but turned out to be more serious. Took it to the garage and they diagnosed a failed EWS (Electronic Immobilizer System) control module, which includes the Hall sensor system. The entire control unit needed replacement and coding. It's definitely not a DIY job since it requires special programming equipment to sync with the car's computer. The repair took about two days because they had to order the part, but the actual work only took a few hours. It's a critical security component, so there's no way around getting it properly fixed. Without a working EWS, the car simply won't start as it's a safety feature. If you're not confident with your current mechanic, I'd recommend finding a shop that specializes in BMW electronics. This isn't something you want done incorrectly as it could leave you stranded again. Best of luck!

Thanks for sharing your experience! That definitely sounds like what I'm dealing with. I went ahead and got it fixed at a specialized BMW shop, and they also replaced the EWS control module. Just curious, do you remember roughly how much you paid for the whole repair? Also, has everything been working smoothly since then? My mechanic mentioned something about potentially needing to replace the key fob in the near future, so I'm trying to plan ahead.

Hey again! Glad to hear you got it sorted out! Yeah, my repair ended up costing around 1000 € to fix the control unit. It was definitely not cheap, but totally worth it because everything's been working perfectly since then. The Hall sensor issue is completely gone, and I haven't had a single problem with the ignition system in the past year. About the key fob, honestly, I didn't need to replace mine after the repair. The EWS control unit fix took care of all the problems. But it's not a bad idea to have a spare key programmed just in case. These old BMWs can be quirky with their electronics sometimes! I'm really happy you went with a specialized BMW shop. These security systems are pretty complex, and having someone who knows what they're doing is super important. Let me know if you have any other questions, always happy to help out a fellow BMW owner!

Thanks for the info! Yeah, my repair bill was about the same. The whole experience turned out way better than I expected. The specialized shop diagnosed it quickly and fixed everything in one day. Funny story, when I first drove there, the car died right in their parking lot! Talk about perfect timing. The mechanic got a good laugh out of that one. He showed me the old control unit after replacing it, and it was pretty worn out. The car's running like a dream now. Such a relief not seeing that annoying key symbol anymore. I'll keep an eye on the key fob, but for now, everything's working great. Really appreciate all your help and advice, saved me from going back to my old mechanic who probably would've just scratched his head at the problem!