Good points here and from others. Makes sense.

I guess the take home lesson is: don't be an idiot and leave your car running whether you have a fob or a real key in the ignition.

I fail to see any good advice here. This is all common sense. Just as the warnings we see during thunderstorms on TV....

"If you see a downed powerline, don't go near it and please call the authorities..."

Really, I shoudn't go out and touch that powerline...shouldn't this be a daily goal and not just apply to thunderstorms?

Why, because we have electronic iginitions, does that make it OK to just leave the FOB in the car at all times? Thanks for making my insurance rates higher. http://i148.photobucket.com/albums/s...8/rolleyes.gif

You may be right. But let's see it this way. When I live in NYC, I lock/club/alarm after parking my car. When going back home in IL, I park my car in front of the house and throw the key into the car. Everyone has the different scenarios and ways to fit into their lives. Ppl may not justify whether or not other ppl do the right thing since they're not making a living under the same "sky". Sometimes our common sense may be different from theirs. :)

Most of ppl here have the valid points.

I was told by Lexus service dept. that I should not leave the fob in the vehicle as the vehicle and the fob will talk to one another but how far away does one need to keep the fob? My fob will lock or unlock my car from any spot in my house so it would seem that the vehicle and the fob are talking regardless of where the fob is so what difference does it make? I am puzzled but I love my 2010 RX350.

Yes, you can unlock/lock alarm the car from anywhere inside your house, or even a block away.
BUT you can't START the car. Try it. Unlock the doors, leave the FOB in the kitchen and go to your RX and you'll see what i mean.

The FOB and the RX talking to each other, continuously is limited to a few feet.

Another experience i had, when the battery is so low, even if you're inside the RX/any Lexus/Any Toyota and you have the FOB with you, you might need to place the FOB as near as 1-2 inches near the Start/stop button to be able to START the engine.

SalmonGuy, as Mark says, just give it a try to see how the distance works. I find how my FOB is designed and operates is just great with me -- with Lexus having put a lot of thought into how to deal with exceptions...

I honestly don't know why I'd ever want to leave the FOB for some long period inside of my vehicle or on the seat -- there have been other discussions on that where someone wanted to hide a spare FOB in the RX, with IMHO the best option being for that owner to just cover the FOB in foil to prevent the FOB communicating with the truck until he wanted it to. You may also want to check out around p36 of your 2010 manual re situations where your RX will stop or slow the frequency with which it searches for the FOB, including how it stops after 10 minutes when the FOB is within 6' of the truck until the vehicle is locked/unlocked -- all designed to help prevent draining the vehicle's (and FOB) battery.

In my situation, I keep my FOB in my pocket most of the time when I'm working or driving the truck, and it hangs on a hook inside my home going out into the garage other times. The notable exception is when I back my RX out in the driveway for a wash, I've learned to keep the doors unlocked, but hang the FOB on a hook I put on one of my interior garage walls -- that way it's far enough away that as I wash and dry the car, but the doors won't lock and unlock magically as water and towels run across the front door handles. Similarly, I've learned I CAN open and close the doors on my RX as it sits in the garage from within most areas of my home, but if I go into the backyard or have the RX sitting in my driveway with my metal garage door shut, the FOB can't get to the RX for the lock/unlock.

As far as if the FOB battery is low, it is a Lexus design point that even if the FOB battery is dead, you can still physically unlock the RX with the key in the FOB, then by placing the FOB physically next to the start/stop button, you can still start your vehicle. Perfect.

FWIW, my 2014 MBZ "FOB" that has the MBZ "Keyless Go" option, operates in a similar manner for all of this as my Lexus. The main difference being the MBZ has a different number of days where it turns off or reduces the time it checks things to prevent battery draining.