My 18 has a lock cylinder on the tailgate handle so I really don’t know why yours wouldn’t because to my knowledge, it’s only there on mine for the same reason why I also have a manual lock cylinder on the driver door handle as well, so that I can gain access in the event of a power failure.
I totally understand the need for a second key that’s either carried on your person, or hidden within your truck somewhere because yes, that other key that’s locked away in your key fob does you no good if you lock the key fob in the truck. Which brings me to my next point, if everything is working properly on your truck, there should be no way to lock your key fob in the cab and the only time I know of where this can happen is if you hit the lock button on the door panel- unsure about the exterior door lock button if so equipped, after you’ve gotten in, got out while the truck is still in remote start mode and the door gets shut. Although when I tested it, I never did wait for the remote start timer to expire to see what happened at that point, I just went in the house and grabbed my spare remote and unlocked the truck.
But yes, you can drive your truck without the fob present but that “fob not in vehicle” warning should prevent that.
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