AW4 post motor swap range sensor issue...

okay history:

2000 non cali emissions xj 4.0 4x4 with a bad timing damper...thought it was a broken skirt and replaced entire drivetrain...

new drivetrain is:

1996 4.0...
1999 aw4 with 50k or so on it...been sitting for 15 months in the garage
Torque converter is from the 2000
Flex plate from the 2000
Transfer Case is from the 1999
NSS is from the 2000

I never read the codes before swapping the motor...

SO...when swapping the drivetrain I mated the 99 tranny/tcase with the 96 motor using the flex plate, torque converter and NSS from the 2000. I was having a starter issue so i pulled the NSS again and re-cleaned and checked it a second time. Discovered the issue was in the connector for the starter switch wire and re-installed switch. Tried aligning the NSS using the reverse lights, but they will not come on. I have not diagnosed that issue, but the Jeep starts in P and N...

First day driving...jeep threw

p1694, p1698, p0705 and an unrelated code for the evap circuit...

the 16** codes are no bus codes for PCM and TCU
0705 is transmission range sensor not detected....

shifted incorrectly, wouldn't lock up torque converter...

swapped the stock 2000 TCU with the tcu for the 1999 cleared the codes...took for a drive and the codes stayed away. trans shifted fine...torque converter locked up. All was happy...till i stopped and shut it off. P16** codes went away p0705 came back. Jeep shifts normally BUT will not go into OD and will not lock up the converter. Stopped...cleaned engine bay connections for the NSS and the transmission sensors...replugged, cleared the code and drove and all was normal. Stopped re plugged 2000 tcu and drove...16** codes ccame back with the 0705. Stopped and swapped back the 99 TCU and the 16** codes were gone again...0705 remained. unplugged and replugged the tranny and NSS engine bay plugs...drove away perfectly normal.

now the cycle continues for a few days and is 100% repeatable...reset codes and unplug/replug connectors. Drive for as long as you want (4.5 hours at one point) tranny perfectly normal...as soon as you stop and shut it off, the p0705 code comes back and you lose the OD/Lockup. Stopping, clearing the codes and unplug/replug works 100% of the time...and the tranny works flawlessly every time.

any thoughts? what am i missing? bad NSS? TCU short somewhere? i don't have a spare nss (the 99 one was smashed and the harness was cut off)

the no bus means that the tcm and the pcm aren't talking. So I would suspectr that something is shorting the tcm and it kills the whole show.

since it goes away after you fiddle with wires and connectors I'd venture a guess that during the motor swap a wire has gotten pinched/damaged and is causing the issue. Pretty sure that the NSS gets a reference voltage, so it may shut the TCM down before it pops the fuse.

swapping to the 99 tcu makes the no bus codes go away though...the p0705 stays . i think i just need to keep nudging the nss adjustment until it goes away. my brain tells me exactly what you say...that there is a short or pinched wire somewhere since unplug/replug fixes it, but its acting like the nss is funky. maybe that just has a pinched wire for the range sensor side of the switch