Grand Theft Auto Online has a passive mode which seems to make you semi transparent to other players and prevent you from arming a weapon but doesn't prevent you from driving over people and seems to have conflicting guidance about it's functionality on various sites.
What exactly does "passive mode" actually do?
Best Answer
This confusion is seemingly caused by the difference in the way passive mode behaves between the original PS3/Xbox 360 release and the so called "enhanced" version released on PC, PS4 and Xbox One.
In both versions, passive mode is only available in "Free Mode". Entering a mission will disable passive mode for the duration of that mission and it will be re-enabled once the mission has completed. Passive mode will prevent you from arming a weapon (except in vehicles, in the original release as discussed below) or otherwise attacking another player or NPC directly. You're still able to drive over NPCs.
In the original version, passive mode is only enabled while on foot - it is automatically disabled while in a vehicle. Additionally, passive players can still be run over or otherwise killed by a player using a vehicle, in that vehicles still hit players in passive mode.
In the enhanced version, passive mode puts the player in a ghost mode, in which they appear translucent to other players and other players cannot physically interact with you while you're in passive mode. When you get into a vehicle that vehicle will also enter the same ghost mode, preventing other players from damaging your vehicle (your vehicle will still take damage from the environment).
Even in the enhanced version, it is still possible for another player to kill you using the environment - for example, blowing up a car that you're standing next to (as the car is "real" for both players) or igniting a gas canister.