It's a 2004.
Every now and then, the dash light that says "4 wheel drive" comes on, when
it's in 2 wheel drive. Also when this happens, another dash light that always shows which wheels are engaged (two wheels solid and two hollow when in 2 wheel, four solid when in 4 wheel) goes completely out, no wheels showing at all.

After awhile, the separate "4 wheel drive" light goes out and the "engaged wheels" pattern light comes back on showing the correct two wheel setting.
No performance issues when this occurs, just weird.

Anyone know how to fix?

never heard of this but imsure someone will shine some light on your situation

I couldn't find anything on that but it sounds like a problem with the electronics. It could be the switch, but is probably more likely to be the ECU that controls the transfer case, or for less of a chance could be the transfer case or actuator (or whatever the 4x4 engager is called) itself. Sounds like a Dealer fix to me unless you know of any good shops who are familiar with the 4x4 components in the Titan and Armada.

Maybe Scr38 or someone else will have a better idea.

It's a 2004.
Every now and then, the dash light that says "4 wheel drive" comes on, when
it's in 2 wheel drive. Also when this happens, another dash light that always shows which wheels are engaged (two wheels solid and two hollow when in 2 wheel, four solid when in 4 wheel) goes completely out, no wheels showing at all.

After awhile, the separate "4 wheel drive" light goes out and the "engaged wheels" pattern light comes back on showing the correct two wheel setting.
No performance issues when this occurs, just weird.

Anyone know how to fix?

Same thing happened on mine a few months ago, but since then I haven't seen it. Gremlins??