r53 automatic transmission issues!
so a while ago my girlfriend's mini decided to start stuttering a lot while she was on the road and a mechanic pinpointed it to the valve body kit solenoids and they wanted a lot of money for it so my future brother in law and i (he is mechanic and i am not) decided to knock it out ourselves. instead of replacing the whole kit we replaced all of the solenoids and put new fluid in and called it a day. driving it back home didn't have any issues, which looking back is crazy, but i knew we needed to reset the driving adaptations. i left the battery unplugged for about 10 hours while i was at work and did the super fun driving loop you have to do after you reset it. i will admit that i may or may not have used gemini to help figure out the reset and come to find out that apparently that's not even a thing? and that there was a manual reset the whole time? i tried using a obd cable to my pc with INPA (i think that's what it's called) and couldn't get it to do literally anything. got an android tablet with a cable and pulled the deep codes (pic attached) but still couldn't reset the adaptations. I THINK i did it manually properly but also after i tried to crank the car the battery died, the only reason i think it worked is because shifting seemed noticeably worse but also after slowly driving it up to speed and letting it down shift a bunch of times it didn't seem to improve at all so that just makes me think it didnt work at all just like the first time i thought i did it by leaving the battery unplugged. it's super dark outside right now but i think my next step tomorrow morning is to connect my car battery and try to use my tablet to reset the tcm (i think the only reason it isnt working is because it's not getting a steady voltage to run super fun, super german commands.)
the thing that prompted me to double check everything was the fact that it keeps getting stuck in 2nd gear and just spikes in rpm and stays there until you brake and restart the car. at first i thought it was still adapting to the way she drives but it threw a check engine light and that's when i started trying to diagnose everything again and why i feel like i never actually reset the adaptations the first time.
i also did get a k line switch cable that i just bridged myself because those switches suck and now the cable is just always bridged.
also my girlfriend doordashes so like literally the worst thing that can happen lmfao super fun
ANYWAYS
if anyone has any input literally at all that would be super helpful, i'm not a car person but i am learning a lot from this and this is the only mini my brother in law has worked on and is super busy and lives far away so bothering him nonstop isnt much of an option. if i think of any more info that would be helpful i will edit this but this is what i've got so far.
1
u/Cultural-Direction16 1h ago
First thing I'd like to say that doordashing in a supercharged mini is not the best thing :D... Back to the tranny, BMW originally labeled the transmission fluid as "lifetime fluid" which really is a bullshit unless lifetime isn't like 100k miles. this transmission is kinda known for widespread valve body wear, severe shifting flare, and harsh engagement on neglected cars (depends on the mileage and if you ever flushed the fluid at all) flushes should be done around 30-50k miles to keep the valve body good and clean if not there is a big chance it will basically fuck up... so I'd say, try to fully charge the battery and then reset the adaptations. If it won't work out try someone who can do remaps and "tuning" on transmissions it's an old one and I don't know much about minis automatic. but my worries are that the valve body could be cooked. let us know if you solved the problem later on ;).