- simple answers to your questions:
Q: How can you tell when the truck goes into regen?
A: If you don't have/use FORScan, you can't tell..
Q: Am I missing something here?
Ford (in their infinite wisdom) chose to not expose DPF regeneration status by default to the end user on this F150 platform.
Regen has been discussed in multiple threads previously and probably the best/most comprehensive thread is: Stuck in regen???
and the best summary is probably Post #67
by yours truly.
If you would like to know when you are in regen, you will need to monitor DPF-related PIDs via FORScan or enable DPF % Full in your IPC via FORScan:
=> You can monitor your Regen status, Miles between Regens, and EGTs (Exhaust Gas Temperatures) via an ODBii adapter plugged into your diagnostics port & free software
=> You can program your truck to expose DPF % Full via a Windows 10 laptop and a licensed software program called FORScan
=> Check out this sticky link I created that explains everything you can do and what you need: START HERE: New FORScan user education
=> This thread here on our forums has the most comprehensive list of favorite owner FORScan mods: FORScan Mods confirmed working
If you have any questions with anything above, don't be afraid to ask questions back here or in the FORScan sticky thread.