Smart key ignition start using mechanical key

Can anyone explain how this works? If the key fob battery is dead, or electronic communication between the smart key and vehicle is interrupted, the manual says 1."Touch the Toyota emblem side of the electronic key to the engine switch" 2."Press the engine switch".

Is the ignition switch embedded with an RFID chip that senses when the mechanical key is in range or what? I've never had a problem with my key fob but I'd like to understand how this works should I ever need it. Can I start the vehicle with just the mechanical key or does it need to be inserted in the key fob?

Also, I have two key fobs + mechanical keys. One is my primary key fob I take with me everywhere. What are you doing with the spare for emergency backup (lost or stolen key fob etc)? I've been keeping mine at home but this obviously won't help in an emergency.

What's the best strategy here?

Thanks!

 

From what I’ve read your truck will give plenty of notice that your fob battery is low.
I think the touch fob to switch is just minimizing the range of fob.
I don’t even carry the mechanical key with me.
I keep my spare fob home

 

The physical key in the factory fob is for your tailgate and glovebox. It inserts into the factory fob for convenience. You can not start your truck with the physical key. As you have stated, place the fob next to the start/stop button & press the start/stop button. Your vehicle will start. If you ever have to start your truck this way, then it's time to switch fobs (since you have 2), or change the battery in the fob that you are currently using... This is the best strategy. Good luck.

 

Interested in seeing the replys

 

Why? I thought I nailed it...

 

Variety is the spice of life my friend.

 

Key also opens the drivers door as far as I know.

 

Correct for starting procedure, and also correct for 2018-2020 model years. Hold it against the button to start.

On the 16s and 17s, the tailgate key was different than the door (and fob) key.

 

Key Fob has a transceiver in it.
1) When you press a button on it, it activates the rfid in the attached key and transmits it over distance to one of the antennas in the truck. From there the ecu does what you asked (unlock the doors).
2) When you touch the door handle or press the start button normally, it receives the signal to transmit and then transmits the id. (Ecu->start the car).
3) When you place the key against the start button and press, the start button activates the rfid directly and it is close enough to receive the iD so the ecu starts the car.

Rfids work by receiving an electromagnet pulse and essentially vibrating at a specific frequency.

 

Really? I have a 2018 Sport and the driver door has a key hole. I made sure the key worked for the driver door, tailgate, and glove box when I bought it. Also note, I have the separate key that works for all those instead of having to use the small key in the fob.

 

Really. No key hole on any of the doors except the tailgate... Not too worried tho. These fists smash glass, daddy o!

 

I wonder if they put a cover over it in 2019. Can you tell if there is a cover that will pop off? This is interesting.

 

It’s official! I’m a moron! Just went check & there is a plug in what i’m assuming to be the key hole on the drivers door. Never even noticed that before, lol. That’s why you’re the daddy o! Thanks!

 

That's not why they call me daddy_o, but we wont get into that here. Im glad to know you won't have to break glass in case of dead battery now.
You're welcome.

 

Understand EM transmissions and how rfids work. #3 is what I'm getting at. I hear you saying that if the key fob battery is dead or can't communicate with the vehicle, the start button activates the rfid embedded in the key fob and receives the ID to start the vehicle. When the key fob battery is charged, and is within range of communication with the vehicle, it's the other way around. Is this right? In other words, communication is always going on two ways between key fob and start button, you only need one to activate the other, and the mechanical key has nothing at all to do with it.

 

You could take the mechanical key out and leave it in the house, the truck will start. All communication is in the Fob.
In fact, MESO has a fob shell that is smaller and does not have a spot for the mechanical key.

 

But if the battery is dead in the fob, you won't be able to get in the truck if you leave the little key in the house.

 

I guess that would bring us back to breaking glass.

I should clarify, I meant for a test to satisfy OPs questions.

With the MESO fob, I guess you need to find somewhere to have the key.

 

Don't mean to heist the thread, but related . . .

Is there I projected lifespan to the fob's battery? Of course I know this depend on frequency of use, etc. When I remember (emphasis on "when I remember") I try to replace batteries before they fail, or have a spare(s) standing nearby. Of course this isn't always practical / possible.

I keep my spare fob at home. My truck is coming up on 3 years old. I would just as soon spend a few extra $$ replacing a battery before it fails, even though there's a backup plan. Sometimes I'm a long way from that spare fob.

 

@ChukarBob Your dash will tell you when the battery is getting low on the fob. But if it’s been 3 years go ahead and change it. I just got my 2017 a month ago and about a week into it my fob battery was failing.