BMW 4-Series Transmission Warning: Limp Mode Alert

Hey there! I experienced similar issues with my 2017 BMW 3 Series last year. The symptoms you're describing match what I went through, erratic shifting, warning lights, and limp mode. Initially thought it was just the transmission fluid too. Turned out to be an undervoltage problem in my case. The alternator wasn't supplying enough power to the transmission control module, causing those weird shift patterns. Had to get the alternator replaced and the transmission control module reprogrammed at the garage. It's definitely something that needs proper diagnosis, these symptoms can point to several issues. In my case, it was pretty serious since the transmission control module could've failed completely if left unchecked. Would suggest getting it checked at a shop that specializes in BMW transmissions. They can run a proper diagnostic to pinpoint whether it's electrical, mechanical, or just fluid-related.

Thanks for sharing your experience! That's really helpful info. I had a similar issue and it turned out to be the control module too. How much did you end up paying for the whole fix? Also, has everything been running smoothly since the repair, or have you noticed any other quirks?

Hey again! Glad I could help! Yeah, after taking it to the mechanic last month, they confirmed it was indeed an undervoltage issue affecting the transmission control module. The total repair came to 240 €, honestly not as bad as I was expecting given how worried I was initially! Since getting it fixed, the transmission's been working like a charm. The automatic transmission oil they found was pretty worn out too, so they changed that while they were at it. No more weird shifting patterns, warning lights are gone, and the car's running really smooth now. Been driving it daily and haven't noticed any quirks at all. It's such a relief when these things get sorted properly, right? I remember how stressed I was when it first happened, but now looking back, it wasn't as major as I thought. Just needed the right diagnosis and fix. Hope your repair goes just as smoothly as mine did! Let me know if you need any other info about the repair process or if you've got other questions!

Thanks! Really appreciate you following up. Just wanted to update that I finally got my car sorted. Took it to a BMW specialist and you were spot on, it was the transmission control module giving trouble. Ended up costing me around 300 bucks for the whole fix, including reprogramming and a fluid change. Had to wait a couple of days for the parts, but honestly, it was worth it. Been driving for about two weeks now and everything's working perfectly, no more warning lights or weird shifting. Such a relief to have it running normally again! Funny how these things work out, was definitely stressing more than I needed to initially. Thanks again for pointing me in the right direction with your experience. Really helped me know what to expect when I took it in. Take care!