Keeping FOB close to the cellphone or other radio frequency emiting device can create interference to the point even good FOB will not be detected. Also I'm not sure if FOB is 2 way device, if it was, keeping it close to some RF transmitter would keep it running at full power trying to communicate, otherwise the electronics could go to low power mode (something similar to sleep mode in your computer) extending battery life. I have my car for 4 months, no problems with FOB so far, just don't get it wet, I don't think the case is weatherproof.

 

If I understand, if I remove the battery from the FOB, I can still get into the car by placing the FOB near the door handle too. And then I can start the car by just placing the FOB near the START/STOP button.

That would suggest the battery is to extend the range and to control all the other buttons on the FOB.

Is that correct?

 

Yes, but I don't think that placing the fob next to the door handle will get you into the car. That is what the metal key is for. What you describe will allow you to start the car, though.

 

A FOB with a dead battery will NOT open a door. Only the mechanical key will do that. Otherwise why would they even include a mechanical key?

 

Dead battery in the car?

Had a friend who put electronic door poppers on his Camaro. No door handles / key locks etc.. Long story short - his battery went dead when he accidently left the lights on. Ended up having to connect a jumper battery from under the car with a jack...

 

Kind of correct! There are three independent keys in the fob:

1) There is a 2 way RF active communications, which is the main "key". When your hand touches either front door handle (on the inside part of the handle), or the trunk lid switch, the car senses your hand and transmits a wake up call to the key. The key then turns on its transmitter to send its ID. If correct, the door will unlock. Similarly, when you push the Power button, a signal is sent to the key for the ID again to insure it is OK to start. Very little power is needed to keep the key listening for the ID request signal, and the transmit bursts and power levels are short enough to keep the fob battery drain quite low. However, it is an always active RF device which can interfere with other very close radio devices, such as a Bluetooth cell phone which is only inches away from the fob (such as when both are in the same purse or pocket). Such a cell phone can interfere with the fob's ability to hear the ID request signal. These request signals and replies work over a range of about 3 feet, and there are 4 separate transmitters in the car: at each front door, the trunk lid, and in the center console.

2) There is a passive RFID tag chip in the fob. It works similar to the RF active chip, except the radio signal from the car (right next to the power button) has enough RF energy to power the RFID chip enough for it to send back its ID. Think of the ID as written on a mirror. Shine a light on the mirror, and the ID gets reflected back! That is analogous to how the RFID chip works. Many cars have this chip in the otherwise mechanical key, buried in the plastic casing at the top of the key. This only works at very close range, but requires no battery.

3) There is the mechanical key slid into the fob which can unlock the car door only.

A more complex, but important subject which I will skip here is how the ID of both the transmitter and the RFID are protected with encryption that makes it very difficult for anyone to eavesdrop to learn your ID and duplicate your key.

-- Alan

 

I would find that a cover would be in the way as I keep my phone charger plugged in there. I don't even close the other lid over the cupholders, so that lid is a waste, also!

 

The non-hybrid XLE have (spring actuated) covers.
My wife's XLE has one.
Things I've observed on the XLE:
With the arm rest in it's forward position (on the XLE it slides) it covers the compartment.
With the are rest in it's rear position my wife places her purse over the compartment and it's weight causes the cover to pop open.
So the cover is either unuseable or open depending on the position of the arm rest.
On my TCH which has no cover I don't miss it in the least.
J

 

Thanks for the detailed reply. So, I took out the FOB battery, went to the car. Sure enough, it doesn't work on the doors anymore (of course the metal key did) and then placed the FOB at the Start/Stop button and it recognized the FOB right away and started as usual. I had thought that a weak battery was required, but there was absolutely no battery. RFID is getting to be more and more popular.

 

How dare you doubt my word!

Just kidding. Thanks for verifying what I understood to be the technology used in these fobs. I had to piece together bits of info from various Toyota sources, and it is always possible that wrong information ends up somewhere, or that I misinterpret what I read. It is nice to know I got this one right, even if I was too lazy to test it myself!

-- Alan