Hello i need help again please, my 2000 mercedes e 320 wouldn't change gears this morning, at first i thought it was because it was 40 degrees cold because after it warm up the gears started changing back normaly, but this afternoon did it again wouldn't shift gears, i been driving in w mode so stuck in 2 gear in 75 degrees temp outside, i end up making it home check scanner code po715 so where do i go from here? is there anything i could check, please reply thank you.