E83 Transmission Problem?

[Imz21]

Hello everyone, I am a long time lurker of these forums and I have had an issue for a month that I have not been able to sort and was hoping someone could give me some insight. Hope everyone is well and safe

2005 BMW X3 E83 2.5L
220,000km or ~137,000 miles
Toronto, Ontario Canada.

Have had this vehicle for about 3 years and fixed a lot of issues with the help of you guys.

I drove it about 2 months ago and it was driving fine. I replaced the steering wheel and disconnected the battery in the process because I had to disconnect the air bag. After I put everything back together and drove it, it was fine. But after a few days when I was driving it it started shifting a little hard. I came to a stop and when I started accelerating it shifted into 2nd and when shifting into 3rd it jumped and threw a trans light on the dash and went into limp mode. Now I tried driving it a little bit in this condition and it seemed to be stuck in gear. It would take a long time to come up to speed and it would not shift. When I pulled over and turned the car off for about 5 minutes it fixed itself. But if I drove a little aggressive it would happen again. On the contrary, if I accelerated slowly it would shift through all the gears.
Now this is consistent problem. Anytime I try to accelerate a little harder it will reoccur and be put into limp mode.

My first idea was that it was low on trans fluid, I never noticed a leak but I thought I would check so I checked and it was properly full. I checked on my own little obd2 tool and i pulled codes

P2096
P0141
P0140

After some research I wasn’t confident that caused my limp mode problems. So I took it to a local Indy and pulled these trans codes on his snap on scanner

149 CAN: wheel speed signal
52 Gear monitoring 2
145 CAN: engine intervention.

He was busy so he wasn’t able to properly diagnose the issue and I haven’t had the chance to go back yet but he’s an old school mechanic, not great with these type of issues. He said maybe a wheel speed sensor. He could be right, I don’t know.

If anyone could help I would appreciate it greatly

Cheers

[vinyldude]

Worn or dirty transmission fluid could be contributing to the problem. Also, about the only easy thing to do would be to change the fluid and the filter and see if it helps at all. I would start with that, but I would keep low expectations. How old do you think is the fluid?

Since the problem seems to be persistent, and "Gear monitoring X" is one of the transmission error codes, unfortunately, this feels like a case where you are looking at either replacing the transmission or rebuilding the existing one. If the code is for real, it is a clear sign that the transmission is slipping and the control unit is not getting the expected gear ratios anymore.