BMW X3 Speedometer Error and Cruise Control Failure

Hi there! I have some experience working on BMWs since I own a 2004 BMW X5 (and previously had a 3-series). I actually faced a very similar issue last month. The speedometer was acting weird and the cruise control stopped working completely. After taking it to my regular workshop, they diagnosed it as a faulty cable connection to the cruise control module. The repair was pretty straightforward, they had to replace some corroded wiring and a connector. Cost me around 95 Euro and fixed both problems. The symptoms you're describing sound exactly like what I experienced, but to be sure, could you share: Have you noticed any other electrical issues? Does the error message appear right when you start the car or only while driving? Which error code is stored in the memory? This info would help me confirm if it's the same issue I had with mine.

Thanks for sharing your experience! Mine's at 122021 KM and had its last service about 3 months ago. Yeah, the error message pops up immediately when I start the car. I haven't noticed any other electrical issues, just these two acting up simultaneously. The error code I'm getting is P1544, which from what I understand has something to do with the cruise control module. Really helpful to know about your experience with the wiring, I'm starting to think it might be the same problem. Did your mechanic have to order any special parts, or was it mostly just fixing the connections?

Hey again! Thanks for providing those details. Yeah, after hearing about your error code and symptoms, I'm even more convinced it's the same issue I dealt with last month with my X5. In my case, the mechanic didn't need to order any fancy parts, it was mainly about fixing those corroded connections and replacing a basic wiring harness that had worn out over time. The whole thing took about 2 hours to fix. And just like your situation, my error message would show up right when I started the car. The P1544 code is exactly what I got too! The interesting thing is that when they were fixing mine, they found that moisture had gotten into the connector over time, which caused the corrosion. Seems pretty common in these older BMW models, they're great cars but these electrical gremlins do pop up after a while. One tip though, make sure they check the entire cruise control wiring while they're at it. My mechanic found a few other spots that were starting to show wear, and we decided to fix those too while everything was opened up. Saved me from potential future headaches. Would you like me to share my mechanic's checklist for this repair? I kept it since I'm a bit of a documentation nerd when it comes to car repairs.

Thanks so much, that's really helpful information! Yes, I'd love to see that checklist if you don't mind sharing it. I'm actually relieved to hear it wasn't a major component failure, those wiring issues sound much more manageable than what I was fearing. I'll definitely mention checking all the cruise control wiring when I take it in. It makes sense to fix everything while they're already working on it. The moisture issue you mentioned is interesting, I'll have them check for that too. It's actually been pretty damp lately, so maybe that's contributed to the problem. I'm going to schedule an appointment tomorrow to get this sorted. Really appreciate all your help and insight on this, it's given me a much better idea of what I'm dealing with. I'll update once it's fixed in case anyone else runs into the same issue!