So the latest warning, my mobile app told me was that the powertrain control module lost communication with rear lighting control module for a period of time. Additional alert may accompany this alert when this fault is present.

Anyone know if this is serious or something I can fix

 

Your "rear lighting control module" is the TRM [TRailer Module]. If you don't tow then I wouldn't worry about it. There are lots of short lost commuication errors that can occur. Usually this happens if your battery SOC is low during an engine start. The module is a little slow to boot up and doesn't send a message when it is expected.

I often have several of these codes hanging around when I connect FORScan. I'm retired, and when it is -30°C outside, my truck can sit for days before I use it. I experince no operational problems and just clear the codes and go on with life.

Clear the code and wait to see if it returns.

 

Shows you have a 2020. Any chance you are still on original battery? Sometimes goofy electrical hiccups occur when battery is low on charge or needs replacement. If you're still original, that would be my first suspect.