Hi,

just wondering if the automatic lock (when left unlocked) on the 1999 ES300 is based on proximity. It seems like when the master key is within 3-5 mtrs of the car our is not locking. But when the master key is 5-10 mtrs away it locks within 30 seconds.

I noticed this because I sometimes park the car about 3mtrs from my desk and walk right in through a door, it might stay unlocked all day if I do that. But if I park near my garage (20-30 mtrs away), it locks shortly after I enter the house.

 

It may have to do with a signal interference where you park. For curiosity, next time try it somewhere else, and see if it makes a difference.

I have a grocery store near me, where in its parking lot my remote never works, unless I'm 1 foot away from the car. Elsewhere it's always fine.

 

I was wondering if the car is detecting the master key is 'out of range' and locks the car. I don't really need to lock my car where I live so I rarely bother too, I just let the car lock itself eventually (or not meh).

 

The way it works, (at least on my 2001, but I believe that your 1999 is the same), is as follows:

If you unlock the doors with the remote, but subsequently do not physically open a door to enter the car in the next 30 seconds, it will re-lock them automatically.

As far as I know, that's the only scenario under which the car locks the doors automatically.

 

The above is correct, it's a safety/security feature. If you unlock the door(s) and then walk away without actually getting into the car, without the auto lock the vehicle would be left unprotected.