Ok, so i tried shifting manually with the TCU removed and it shifted into all gears except second... Not sure how to get it from first to second but it wasn't doing it by itself.
Shifting to 2nd is automated from engine rpm, load, etc. (the TCM and PCM are connected sending information to each other)
I've only done mostly transmission maintenance on the AW4, replacing fluid every so often, haven't had to remove, replace or overhaul. Has close to 200,000 miles, still running well, haven't had any problems as of yet.
Here are some initial preliminary diagnostics, things to inspect.
Check Fluid Level
Check Fluid Condition
Inspect harness connectors for corroded, damaged, loose or backed-out terminal pins.
TCM
TPS
Solenoids
TRS (NSS)
* Also you might want to inspect and clean the grounds, around the TCM where it's grounded to the body. There are other grounding points that can potentially effect the transmission and shifting. The TCM, TPS, Solenoids and TRS all have ground connections. I can't remember off-hand exactly where.
Shifting works basically from the solenoids opening and closing fluid valves.
Solenoid -- #1 --- #2 (are used for shifting)
1st Gear -- ON --- OFF
2nd Gear - ON --- ON
3rd Gear - OFF --- ON
4th Gear - OFF --- OFF
Solenoid #3 is used for the torque converter.