New (to me) Gen 4 - Key fob doesn't work / can't start - recommendations?

Hey folks,
I'm a bit of a shade tree mechanic. I have refurbished a number of older Gen2 Prii and then give them away to folks that need them. (so familiar with Prii / keys / etc).

Wanted to upgrade my personal fleet and bought a 2022 AWDe from a salvage site. Looked decent (soft hit in rear quarter) - said "doesn't start" - I can figure that out

Received the vehicle on a tow truck, jumped it, supplied key doesn't work (thus no neutral so had to drag it off the trailer - so fun...)

Charged battery, vehicle says all the things it should (depress brake pedal, bring key to the power button) but the key fob does not remotely lock/unlock AND does not work with the "hold the key near the power button to start"

Wrong key with the auction? But the mechanical key works so I think it is the right one.

At this point, my thoughts / debug paths are:
1) Fuses: Check all the fuses - hopefully something bad there
2) ECU reset: Something is bad with the ECU - any way to "reset" the system? Assuming that just a standard "disconnect battery" should be sufficient
3) Re-associate key: Drag the car to the dealer and ask them to rekey it? Do they need the car and key? Can any standard locksmith do this?
4) Replace ECU: Something is _really_ bad with the ECU - replace?

Anyway, I'll slowly step through my tree. Figured I would put this request out to the interwebs and see if anyone has some good recommendations.

Thanks!

 

Thanks for the responses.

Fuses? A-ok.
ECU reset? did the "no battery" for 5 min thing, no change.
Yep, tried another battery in the fob. No change - still get the LED flashing but the key<>immobilizer comms seem no good.

Didn't know I could pull OBDII stuff without turning it on. Will try that next.

Looked around the trunk and didn't see any disconnected wires (the interior is all ripped out of the back to do some body work) - I think I know where the traction battery disconnect is. Will check.

Call the dealership (in norcal - not the cheapest area) - they said $250 to re-pair the key to immobilizer and if that doesn't work, $750 in labor to replace the immobilizer (the part is $130). The biggest issue for me is dealing with the immobile rock of a vehicle (no neutral - and they need the vehicle and key at the same time).

Called a locksmith - did not get a good vibe that they knew how to do the re-pairing.

Was bummed that priuschat was down last night and a good portion of today. Will continue the research into replacing immobilizers (I suspect that is where I am headed).

 

Ok, quick update. Got a locksmith over. He was able to reset the car (basically using the process here).

After reset, the original fob was able to re-pair to the car! The two new keys I bought from keylessentryremotefob did not program.

Fun follow ups:
1) the factory key fob works great inside the car for start but does NOT work wirelessly (buttons don't work, remote does not flash when I approach the car). I suspect a bad fuse. I thought I checked but I did not "pull" and then check - I checked in system. Will try again.
2) the fob vendor said techstream couldn't use their keys (as they were refurbished). I suspect that they were used and then never re-zero'd out. Will have to figure out the method to zero a key or buy ones that have never been used.

Let me know if any thoughts on 1 or 2 above. I'll update the thread as I learn more.