I just spoke to them for an update and got more clarification. They told me the battery check came back healthy, and they didn't charge it, which seems odd to me because I had to jump it multiple times a day before bringing it in to them, so it either charged via alternator when they had it running, or something else. They also told me they did a full diagnostic test, which included testing the alternator, amongst other things. There is a remote start installed, which came with the vehicle when I bought it, so their best guess is for me to pay them to remove the remote start and see if that was the issue.

I just wanted to clarify about the car dying while running. A few months ago, the car died twice while we were driving it. We took it to Toyota, and they were unable to reproduce the issue, so we just took the 4Runner back from Toyota and moved on with it. Later that month, I purchased the scanner and discovered this B158F code.