[cholmes16]

Over the past 4-5 months, I have had a couple of transmission malfunction errors on the screen. I couldn't tell you what was done to trigger those messages as they just seemed to appear out of the blue. Pulling over, turning off the car, and restarting it made the messages go away. In addition to those couple of error messages when I am driving on the highway at 60+ (so at this point I am somewhere around 2500 rpm) let's say I have to really step on it...then when I take my foot of the accelerator the rpms get kind of stuck around 3000-3500 and don't go down unless I brake. I once had a transmission error a year or so ago (since resolved by changing out a sensor) and it caused my car to go into that dead mode which scared the heck out of me and I am paranoid of that happening on the hwy when I'm driving 80 mph in the left lane! So I want to get this taken care of.

So what should I do? I have the dealership who probably wants to take me for all I'm worth... They said they want to charge me the $130 for the diagnostic test and then go from there. That when this kind of thing happens it is rarely a matter of changing the transmission fluid and changing out a filter. Usually, they say, it is a computer issue which would require resetting it or downloading something. (What does that cost?? They wouldn't say; they want it in there all day first)

Then I have the German car repair shop where the guy says "Eh it's probably just that the transmission fluid needs to be changed and that's a great chance to change the filter as well". And that's only a couple hundred bucks. But if it isn't needed and doesn't fix the problem......then?

My car's got 120,000 miles.

So, which place should I go to? Is it typical to need new transmission fluid? Or is this usually a computer problem?

Thank you for your help!!

 

[JayDee4711]

At 120k, changing the transmission fluid is overdue. If it was done at half the mileage, it would not hurt, but then your symptoms would likely have a different root cause.

What German manufacturers call "lifetime filling" refers to the lifetime of the transmission, or maybe the original lease, but not the car.

Your description almost sounds like the tranny is slow to downshift. Then, when you do a kickdown, it is stuck in the lower gear. Do you have automatic or SMG?

 

[cholmes16]

It's an automatic.
I'm not sure if the transmission fluid was ever changed...it might have been...I bought the car @ 90k miles.
Kind of sounds like what you're describing except once I brake, it gets "unstuck" and works like normal. It only seems to get stuck when I am accelerating quickly from a high speed. I hope that makes sense? I am not a technical car person ;-)

 

[JayDee4711]

If you do not have a service history, I would definitely change the tranny fluid and filter (which is part of the pan). If your tech knows his stuff, he will be able to tell you quite a bit from the color and smell of your old fluid. If he doesn't, you might want to try and find a better one.

Talking about fluids, your car has three differentials, front, rear and transfer case. Their "lifetime fillings" are probably due, too.

 

[Jtbgonesailing]

+1 on the ATF fluid change. I would add, have the tech reset the transmission adaptation with BMW proprietary software. Same for the transfer case fluid change and resetting of transfer case adaptation... Fluids are cheap compared to replacing components.