2008 Prius No Start issue

Hey There, New guy here. I've been searching and searching the forum for information on my issue and I haven't found anything exactly like what I'm experiencing.

Here is a description of the issue and what I've done/checked as I can.
I only have one fob for this car. The rubber part has been deteriorating for some time and recently started acting up by not starting the vehicle without being in the slot, not unlocking the doors by door handle touch, and the lock/unlock buttons not always working. It was never in water. I replaced the battery in the fob even though the red LED was lighting up when buttons were pushed, no change.
I finally picked up a new case for it and transferred the board to the new case. Fob starting working again as normal...thought maybe lint and dirt and dust had collected on the board and once cleaned out and put in a new case problem was resolved. This lasted about 2 months. Last week it started acting up again, not unlocking doors, having to be in the key slot to start the car etc. Buttons are not stuck down, battery is not dead.

2 days ago, key does nothing. Car will not start or respond to the fob at all. If the fob is not in the slot the dash shows the yellow key when brake and power are pressed, when the fob is in the slot there is no yellow key but there is no response from the car at all. When the fob is in the slot and the door is opened the car beeps to alert you the key is in the car. Otherwise that is the only thing that happens to indicate that the car recognizes there is a key at all. No green "ready" signal in the power button. Only an occasional relay click under hood and the buzzing/click that often happens as the car is powered up or shut down. The only light on the dash is the flashing red car with the key inside it.

Things I've done/checked:
checked 12v battery(which I replaced in 2018)and it read 12.4v after my daughter had been trying to get it started for a while.
Put on charger(took less than 30min to show full charge)holding at 12.7v now.
Headlights are strong and all other lights work power locks are strong and not sluggish from the door switch
Checked the Key push button below steering wheel, it's out.
I even jumped it just to make sure as I have had to jump it in the past when the old battery was nearing its end
I checked every fuse under hood including the AM2, all are good(was hoping this was just the inversion pump issue)
I checked the negative battery cable to car connection
Unhooked the negative cable for a period of time to hopefully "reset" it
Held the power button for 45+seconds
Disconnected and reconnected the hybrid battery

I think that's everything I've done
Is is possible the key just finally gave up the ghost? Is that a "normal" issue? I really don't want to tow this to a dealer, but it's looking more and more like that is going to be unavoidable.
Any help would be greatly appreciated.
Thanks in advance.

 

Thanks for the welcome. I wish I was joining under different circumstances lol.

At the positive post it is 12.52volts

SM-G981V ?

 

Yes

SM-G981V ?

 

Anyone have anything else I can check before towing to the dealer?

SM-G981V ?

 

So you think the fob has finally given up on me? I just can't think of anything else based on what I've already checked.

I didn't know if the receiver in car could be the issue, or some other "immobilizer" circuit of some kind.

I'm at a total loss if it isn't the fob.

And thanks BTW for chiming in, I appreciate it.

SM-G981V ?

 

Well, I ordered tech stream yesterday so we'll see what I find out in a week or so.

SM-G981V ?

 

Well, now if I could just get past the registration in techstream I'd be closer to figuring something out

SM-G981V ?

 

I am an idiot.

When I switched out the board to the new fob case I thought the chip was integrated into the board on the sks fobs...
No rfid chip, and now that the sky functions are totally kaput I'm dead in the water. Contacting dealer to see what the cost will be since I can't get techstream to work and am skeptical about buying reseed codes from overseas...expensive lesson

SM-G981V ?

 

After about 2 weeks I ended up throwing it away...I NEVER throw stuff away...just for reasons like this...until now.

I can't believe I did this.

SM-G981V ?

 

Being towed to the dealer this morning...sad day...lol

 

Dealer quoted me $150 for the fob, $60 for the programming which I was thrilled compared to other stuff I'd been seeing. I got a call telling me they would need to reseed for a new fob, that the car wasn't recognizing my fob and it would be over $500.

I'm like, I already told you this fob was missing the RFID chip, that the SKS functions weren't working, and that I would need to tow it there...I thought that was enough information that you were going to need to reseed, why did you quote me the $60 for programming a new fob as if I already had a working fob that could be used as a master when I already told you it didn't work?

He said the fob wouldn't be $150, more like $250...I said, whoa, the lady yesterday in parts told me $223 if I needed the hard key with it, $150 without the hard key...then said they don't even have a woman that works in parts...I'm like then who did I talk to?????

Finally he talks to the service manager, finds the $150 fob that came in today, and says it'll be about $380 then with the fob and reseed. I'm crossing my fingers that I don't get another call.

What an expensive lesson. Now to find another sks fob I can buy and program so we have 2 working fobs...
I also only have 1 fob for my 2011 I just picked up, I better get a backup soon for that one too.

 

So $384 later I have a new working SKS fob. They told me that the old fob was no longer recognized by the car but that the fob was still working. I'm not sure how they new the fob was still working other than the fact that the LED still lights up when pressing the buttons, they said it appears that the car "forgot" the old fob.

Here I am 6 days later, my daughter just texted and said she hit the power button and the car said the key wasn't in the car. She tried it a 2nd time...still said there was no key in the car. 3rd time it started. She didn't attempt to put the fob in the slot...just kept trying the SKS functions.

Is this an ECU issue that the car is having trouble remembering fobs or the receiver antenna not getting the signal to the ECU??? So frustrating.