2000 S80 T6 Transmission Limp mode 3rd gear

[atomic928]

I know this has been talked about a lot but I just can't find the correct solution to fix my problem. On my 2000 S80 T6 with 171k miles when I drive for about 10 to 15 minutes and get up to speed, 40-50mph, the check engine light comes on and my transmission will not come out of 3rd gear, I know this is the 'limp' home mode. I can stop the car, turn it off then turn it on again, and the tranny goes back to normal and again shifts 1-3 fine until the 10 minute and/or speed mark is reached then back to limp mode. I can hook up my odb and I get shift solenoid errors. I replaced all the solenoids, I think two, in tranny, along with flushing the tranny twice and new gasket/filter/oil. The limp mode seems to take longer but still comes into play. I think the wheel bearing is going bad so I'm going to replace that next and check the speed sensor and replace if needed. But what makes my case seem unique is that I can turn the car off/on and it resets the tranny, I know some time make before all the repairs, off/on would not do it I had to use my ODB reader to clear the solenoid codes to the tranny shifting again.

So my question is does anybody have any other suggestions as to what the issue might be, besides replacing the tranny? I feel it more an electrical related issue, sensor, wire, something down those lines. I also read some people said something about a bad throttle body might be causing the limp mode but the engine runs fine.

Any help would be appreciated.
Thanks in advance.