I've been busy tracking down an AW4 problem too. Had a MAP and Cruise code fault and it was running about 300 RPM too high while cruising. No torque converter lockup I surmised. I tested the solenoids at the 7-pin grey plug at the back of the engine bay (easier than at the TCU connector), all were right at 15 ohms. Changed out the MAP, no help.
The next step was to pull the speed sensor and bench test it like here: http://www.ehow.com/how_7683994_check-transmission-speed-sensors.html. But first I checked the brake switch. When the pedal is up (no braking), a closed contact completes the circuit to the TCU and allows TC lockup. When braking the switch opens unlocking the TC. My brake switch was not closing all the way to allow continuity to the TCU, so the TC wouldn't lock up. All it took was an adjustment and the TC locks up fine now. No more fault codes either. Sooo Jake-man, check your brake switch contacts before pulling the speed sensor.