2000 XJ with NP231, wouldn't shift out of 2nd. Like in a limp mode. Found another AW4 and swapped it out, bending a flex plate in the process. (Didn't fully seat the torque converter before bolting bell housing to engine, Arrggh!)
Turns out it still has the same problem with the new trans. installed. Switched out TCM with sons '99 XJ TCM to see if it was a bad transmission control module. Still did the same thing with his TCM installed. OBDII not showing codes. Unplugged it runs in 1st only. Suspect a wiring issue now, any ideas or similar situations?