I want to thank this forum for leading me to the right answer. Like many posters have already said, my 2015 Nissan Leaf got this error code all of the sudden. The car won't start, the screen went spastic, with the "T/M Vehicle System Malfunction Warning. See dealer." error intermittenly showing.
After reading this forum's experiences, I concluded that the battery was the most likely issue.
Thankfully the car was in my garage at the start of the weekend, so I didn't need to tow to a dealer. I went to Costco, brought in my old battery, purchased a new one for $82 (which included the $15 core fee / recycling fee, and taxes), and changed out the battery myself. It worked! I'm grateful that this all happened on a weekend and at home, and for the guidance this forum game.
Thanks, everyone.
2015 Nissan Leaf
It is now Nov 2019, so the 12V battery was ~4-5 years old
Total cost: $82
Total time: 3 hours, including initial diagnosis using a multi-meter to measure the battery voltage and confirming that it was at 11V, taking out the old battery, going to Costco, coming home, and swapping out the battery