Key Fob Doesn't Start Car When in Slot

I'm going to suggest you first replace the battery in the key fob. I believe it's a CR2032. Then let us know if that resolved the issue for you.

Assuming that works and you can now start the Prius with the key fob in the slot, then yes, you can buy a key fob (either official OEM w/ Toyota logo, or a 3rd party one. but make sure to get a new, virgin, unused one to make the process easier for you) and then do the "chicken dance" (search for it) so that you have an extra key fob.

You definitely don't want to skimp and try to get by with only 1 key fob. You should always have a spare key fob because it'll cost a LOT more to get a new key if you ever lose the only key fob you have.

 

Something's a little confusing in the OP.

The fob can be used two ways to start the car. The smart-key way, where the fob can stay in your pocket in the seat, depends on the small battery in the fob (and the car has to recognize the smart-key ID the fob carries).

The proximity way depends only on the small RFID chip contained in the fob. It doesn't depend on the fob battery. Also, the car has to recognize the RFID chip.

Where you put the fob to use the proximity way is different between Prius generations. In a gen 2 Prius, there is a slot you stick the fob into, which is where gen 2's RFID antenna is. In a gen 3 Prius, there is no slot, and you hold the fob right up by the power button, which is where gen 3's RFID antenna is.

The idea of being in a gen 2 and trying the fob next to the power button instead of in the slot is kind of puzzling, and doesn't really give me a clear idea what might be up.

Does the car start if the fob's just in your pocket?

 

Good electronic locksmith now have tools that can read your on car transponder info behind the heater box without accessing it. Then they can use those numbers to clone you up a transponder chip. Vvdi key tool can do this

 

First of look under steer wheel is their a black button marked key if so go on eBay and buy a used SKS silver logo 3 button factory remote not the fakes . Then once In hand call lock Smith . You could try the chicken dance . Instead of slotting remote I the dance put it next to button wen required can't hurt to try . I'm wondering if ya hold remote in front and touching slot door do it start then?

 

The strange thing is that I don't think the key fob would work at all if the RFID chip isn't in it. And I agree with ChapmanF's post above regarding the "antennae" for the key fob.

For Gen2, in the situation where your key fob battery completely died, you should still be able to start your Prius by using the physical key to manually open the door, and then insert the key fob (with dead battery) into the slot, and press Start. So one suggestion to troubleshoot your issue is to completely remove the CR2032 battery from the key fob, and then try inserting that into the slot to see if you can start the Prius.

For Gen3, in the situation where your key fob battery completely died, you should still be able to start your Prius by using the physical key to manually open the door, and then "hover" the key fob (with dead battery) over the Start button, and press Start. Since your description in the opening post implies that's what you were doing, can you positively confirm you have a Gen2 instead of a Gen3 Prius? Maybe post a quick photo of either your key fob or your dashboard showing the key fob slot and/or Start button?

Another suggestion is to insert the key fob into the slot "upside down" to test if orientation matters in your situation. I usually insert the key fob with the buttons facing up, but I'm pretty sure it would still work if I inserted the key fob with the buttons facing down.

 

Does it start the car that way for both positions of the KEY button under the dash?

 

You're mistaken, SKS unlock/lock and start, and/or remote unlock/lock both work without the RFID as long as the fob battery is not flat (< 2.9V). Whether there is a flat fob battery or not, with a missing RFID, the car will not start with the key in the slot. The whole purpose of the RFID is to provide a fallback for when the fob battery is flat.

As the OP has already stated, he has already tried that, and the car will not start.

The OP has already stated he has inserted the key fob into the slot, which should clarify whether the car is Gen 2 or Gen 3.

It makes no difference. I have inserted the fob in both orientations many times, and the car has started fine.

The only thing odd in what the OP has described is that the car will not start with the fob in the slot or if the key is in his pocket, but will start if the fob is held close to the start button. This makes me want to think the fob battery is weak, so maybe that new battery is not so new in reality.

 

Again will it start if you hold it against the slot not in it the antennae is in slot and around it . Over near button you may be just inline better with antenna .

 

You're correct about the RFID and thanks for the clarification. I should've been more accurate in my statement by saying that 'I don't think the key fob would work at all [in the key slot] if the RFID chip isn't in it."

I asked OP to try the key fob without a coin battery in order to try to diagnose if the issue was a faulty new battery.

Since the OP's initial description was evocative of both a Gen2 and Gen3, I was just asking for clarification.
OP said "I have to put the key right next to the push to start button for it to work."
I (and I believe some other posts above) interpreted "it" as referring to the closest antecedent ("push to start button") instead of the next closest antecedent ("key"). So I read "I have to put the key right next to the push to start button for the push to start button to work." Therefore, that description sounded like a Gen3 instead of a Gen2.
However, you read "I have to put the key right next to the push to start button for the key to work." With this interpretation, I do agree with your conclusion that it seems like the key fob CR2032 battery needs replacement. But OP already stated it's a new battery.

So now I would ask the OP to actually test the new coin battery's voltage with a multimeter. IIRC, the multimeter should show the voltage of a new CR2032 as something like 3.3 V.