I have tried disarming with the key. I am not certain if it was factory or dealer installed. I have not been able to find any kind of reset switch under or around the dash. From what I have been able to find, nothing in the manuals say that you can disarm with just the key, unless the system is in passive mode. It just seems odd that if this is how it was designed, that no thought was given to being in the middle of nowhere, and having a malfunctioning remote and no way to start the car.