I have a 2002 Camry with less than 100k miles that all-of-a-sudden stayed locked in reverse and neutral. I can shift and it sounds like the transmission is shifting, but when in reverse and neutral, the vehicle acts like it is in park. The console shows the correct gear position.
Occasionally, reverse will work, but most of the time it will not.
The transmission fluid is the correct color and level, and doesn't smell burnt.
I think the parking pawl might be stuck in reverse and in neutral.
Is there anything outside of the transmission that could be causing this? I suspect not, but would obviously like to check all potential problems before concluding the transmission is broken internally.
Drive, 2nd, and 1st work as expected. There was no indication of any problems prior to the reverse being locked up when shifted into reverse.
I did a OBDII scan of the vehicle and not codes came up for anything.
Any help or guidance is appreciated.
Notes -- When I cycled through the gears in an effort to check the level of transmission fluid, reverse all-of-a-sudden popped into gear when I was moving from 1st towards Park (holding about 5 seconds in each gear). There was a "clunk" sound and I felt reverse fall into gear.

 

Is the shifter gear selection NOT in sync with the actual gear? Here the gear selector can be in D, 2nd or 1st and the trans can go into reverse?

The trans housing has a shifter rod that extends outside the case. A shift arm mounts to the rod. Determine if the arm and rod are securely attached.

A push pull cable mounts between the shift lever and the trans shift arm. Have someone move the shifter lever between gears as you watch the shift lever on the trans move. Determine if the shift lever and rod move in sync with shift lever. If the ign key and brake is ON, one can do this with the engine off for safety.

The trans also has an electric shift, check for wiring issues.

 

Everything is as it should be within the cabin environment -- the physical shifter moves, the console shows the right gear, and I can hear the transmission/engine change sounds with each shift into reverse and neutral, but the transmission is locked down like it is in part for both reverse and neutral.

I believe you are talking about the mechanism that attached to the engine end of the shifter cable. A visual inspection indicates that everything looks to be in place, but it definitely looks only and rustyish. I can't tell if all the adjustments are correct or not, just that the connections aren't obviously loose.

One person shifted and one viewed the engine end of the shifter cable and it moved with each shift but I couldn't tell if it is out of alignment or not.

Those wires go to the device behind the shift arms, right?

Is the similar to the process you are suggesting?

How To Adjust An Inhibitor Switch

How To Test and Replace the Neutral Safety Swtich / Inhibitor Switch P0705

​​​​​​​Thanks for the reply!

 

Is the transmission really locked up? Try pushing the car to find out.