AW4 not shifting, everything tests good....

I have both the AW4 service manual, and the shift pointers documents, and reviewed both many times.

Jeep is an '89 XJ, 4.0, AW4. Was shifting fine, t-case was replaced, and it no longer shifts out of first gear. We unplugged the TCU, and it shifts fine manually. I probed the TCU connector, and got the following:

neutral switch 1/2 - battery voltage
neutral switch D - zero voltage
brake off - zero voltage
brake on - zero voltage
TCC solenoid - 13ohms
Shift solenoid 1 - 12.5 ohms
Shift solenoid 2 - 11.5 ohms
TPS 5 volt supply - 5.5 volts
TPS signal - 5.3 to .5 volts
Direct battery feed - battery voltage
ignition feed - battery voltage

We got another TCU from the junkyard, and it didn't fix the problem. We also took a drive around the block, and I backprobed the shift solenoid 2 wire, got the jeep up to 30 or so, and it never sent a signal to turn on the second shift solenoid, hence why we thought it was a faulty TCU given that everything else checked out.

I was a little concerned about the NSS giving zero voltage in the D position, but I thought it would still at least shift into second.

I'm not sure what is going on now....

I believe the NSS sends a signal for 1-2, 3, R and P/N, but it does nothing in D. Why there would be a pin for it on the TCU, I do not know. According to FSM the switch does nothing in the D position. Incidentaly 4th gear also involves no input to the solenoids. But this does nothing to solve your problem. Check that wiring between the TCU and sol2. My brake switch for the trans has never worked, so that isn't it.