If your truck did not come from the factory with a VSIM module installed, it is not enabled. This is not a guess.Just went home to try grounding the input. And no go. V sim only functions with key on. Still I don't know if my truck has the vsim enabled I'm guessing it does but only because I found the 6 wire connector under my dash that had power ground and can lines going to it. Out in my fuse fuse panel I found a fuse that was labeled vsim2 and when fuse is removed I lost power to that connector.
Just get AlfaOBD, the bypass, the OBD interface, and enable the VSIM in the BCM and be done with it…please…