srs5694
Active Member
I agree with @mswlogo. When I'm at home, I keep my cell phone (a OnePlus 5t running Android 9 -- although it ran Android 8.1 when I first got my Tesla) on a table in my kitchen. Depending on where I park, this is anywhere from 4 feet to 25 feet from my Model 3, albeit through a wall. Even at the closest distance, I cannot open my car's door when the phone is inside my house; I have to have the phone on my person for the phone-as-key function to work. I've also observed, when washing my car, that if I leave the phone about 5 or 6 feet from the car, in direct line of sight (no walls in-between), I can't open the car; I have to bring the phone closer to the car for the phone key to work. In most of these cases, the Tesla app reports that it's connected to the car, but the car door remains locked. It's pretty clear that the phone-as-key feature is working on something other than a simple presence of a Bluetooth connection. My guess is there's a measure of signal strength and/or triangulation to measure distance. (I haven't looked at this in depth, but my phone reports four Bluetooth devices with long gibberish names when it's near my Model 3, and some have suggested that these devices are used by the Tesla to triangulate on phones.)
One more point: When I walk away from my car, I can hear and see the outside mirrors fold. This typically happens when I approach my house's front door. Whether that's distance or timing I don't know. My understanding, which may be wrong, is that the mirrors fold at the same time that the car locks. Thus, if the mirrors fold, the car should be locked -- although of course it can be unlocked if a phone set up as a key is close enough.
That said, in discussions of the phone-as-key functionality elsewhere on this forum, it's clear that there's a lot of variability from one phone model to another, and in some cases even one phone OS version to another. It's entirely possible that my phone's signal strength (or whatever) is strong enough for it to work reliably but weak enough to not work through a wall or at a distance of over 5-6 feet; but another phone's signal strength might be great enough for it to work at a greater distance. If somebody has the problem of the car staying unlocked even when the phone is inside the house, I'd suggest pairing another phone (of a different brand), turning off the Bluetooth on the first phone, and testing with the second phone. If the problem persists, take the car to Tesla for service, since that's not the way it works for most people, and it's likely not the way it's supposed to work.
