We have a relatively new to us Ford Explorer with two fobs, one came with vehicle and one after market. My question is does the same key fob have to be used for a “single” trip. Here’s an example: I drove home from work last night and picked up my husband for dinner. Outside the restaurant, I got out and he went to park the car. I had my key fob with me and he had his with him. I took the key fob that had been used to start and drive the car and when I walked away, he got a warning that the key had left the vehicle even though he had his key fob with him. Should this happen? So, essentially, does the same key fob have to be used throughout the whole time and engine is running?