Need Help: 2002 Prius all the keys are lost

Following up:
Immobilizer ECU part number is 89780-47010, with a sample price of about $300.
Immobilizer ECU, 3 keys and all locks, 89709-47010, sample price of about $700.

MoriD, the Gen I Prius ECU allegedly can be reprogrammed (outside the car) to take a new key, but
(a) that requires extraction of the ECU from the car
(b) finding someone who can do the reprogramming (not a dealer option, here)
(c) hoping that they don't mess it up, and
(d) still leaves the problem of how to unlock the vehicle... for which you need the key code. Toyota dealer can get that code via VIN lookup, and it is also somewhere inside the passenger side door (which requires partial disassembly of the door).

Summary: as pointed out earlier, losing ALL keys is an expensive (time and $) error.

Parts Links: Not recommendations, just pointers.

89780-47010 - Toyota Parts Deal
89709-47010 - Toyota Parts Deal

 

As of Dec 2017 I have a few Gen1 immobilizer ECU's with a matching master key for $180 shipped. If you can get a key made that will turn in your ignition this is all you will need to start the car. Tell the dealer you want a "plain silver key cut by code that will open the trunk". They can cut the key via the VIN and a copy of your registration. As long as nobody has changed the locks in your car the silver key should turn in the ignition cylinder.

You will have to replace your immobilizer module with the one I supply which requires taking the dash apart but it will likely be your cheapest option. Boulder Hybrids (303) 325-7411

If you have a Gen1 with only 1 key please try and deal with getting an ADDITIONAL KEY BEFORE you lose your last key.

The video in this link could help you;
Gen1 Prius, make sure you have a backup ignition key! | PriusChat

 

I have also lost the only key to one of my 2001 Prius. From all the searching, I have determined that the immobolizer
box behind the steering wheel buried in the dash has a eeprom chip on it that stores the chipkey ids.
I have taken this box out of the car and attached an eeprom reader to the 93lu66 eprom chip, and can read out
the contents and write it. However, I've had no success in getting the updated contents getting it to go into initialization mode
to accept new keys. There was a writeup for a different toyota, and the eeprom data is different than the prius as far as I can tell.

It appears you can buy the 'virgin' eeprom contents from some locksmith suppliers, but I'm hoping someone can help with what
the eeprom contents should be to get it to initialize. I've tried to blank the it (all FF), and zero out all the existing key ids,
and the 03 counts, didn't work, then zero the other data, and that didn't work either. So I'm missing something.
Appreciate any help, this is a $600 car, can't really spend $200 to get a working key.. thanks for any help

 

$200 more for a working car.
Or have a big lawn ornament.

Alternatively you could try to buy another non working car that has the parts you need. That might save you $50-$100.