This is the same code as last time (1.5 weeks ago). I'd feel fairly confident it has nothing to do with the cruise control switch which is what the dealer said it was (shorted out). They replaced it yesterday and the same issue happened on my way to work this morning. Guessing its an upstream problem.

Same thing happened on my way to work this morning as it did last time this happened - its like its lost power. I can mash on the throttle and there is nothing there - I'm wondering if its stuck in a high hear and won't downshift, that is what it seems like? Might explain why it doesn't seem to have power as its in too high of a gear, but that doesn't fully make sense. Next time it happens, I'll try and manually shift and see if it runs normal - it may not if its getting stuck in a higher gear?

Anyone had this issue and the P0729 code?

This code is triggered when the trans does not shift into 6th gear as instructed by TCM.

Causes: Electrical malfunction (circuits open or shorted) OR mechanical malfunction (control valve sticking, improper solenoid valve operation).

Likely problems, in order of likelihood:

Low fluid level
Shift solenoid mechanical fault
Hydraulic circuit fault
Transmission failure

Check fluid level per FSM (available at nissanservicemanual.com), change fluid, and clear codes. It's still relatively new, so I wouldn't suspect a major malfunction yet.

Nissan is sending dealer a new transmission under warranty. My Armada has been sitting at the dealer for over a month. Hoping to see the transmission by the middle of Dec. Fingers crossed.