Remote no start lights blink?

Most of the time when this happens the battery is bad and needs to be replaced, I would take the battery to the auto parts store for load testing. If the battery is okay check the hood switch, if the hood is open the truck will not crank and blink the lights. You must press the brake pedal before cranking, you probably know this but I need to mention it. Can I ask if the security light is flashing? I have seen the PATS system disable the starter and blink the lights as well. If you can lets do a CAN scan.

CAN SCAN - https://youtu.be/u-4syLc-ifQ

This will let us know for sure what is going on. Let us know how it goes, Ken

Is the remote start after market? If so this can be the problem, I have seen many aftermarket remote starts just stop working, no code of course because the computer does not recognize the feature. This truck does not have a hood switch in the security system so the system must be aftermarket which is the problem. Please send me an image of the remote so I can tell for sure.