2014 4.3L 140,000MI …just started having this issue the last two mornings driving home from work. I disconnected the negative terminal to shut the fan off because I was worried about killing my battery, but didn’t try to restart the truck for hours. I noticed my coolant was low, so after the engine cooled down I added some to get it to the cold level marker located on the reservoir. Drove it around for 20 minutes, Let it sit for an hour or so, then took my 40 min drive to work (both highway and city driving) with no issues. Then on my drive home in the morning the issue started again. Disconnected the negative terminal once I got home, reconnected after a couple minutes again, but this time I started the truck immediately, and the issue was gone again.
Has anybody come up with a solution yet? I’m going to check out wiring and replace the ET sensor when I get up this afternoon, but after reading this thread I’m not feeling very optimistic about that fixing the issue.