Adding door lock sensors?

The answer is NO. I don't think it's an easy mod to convert 1 door SKS to 3 doors SKS. Actually, for Prius PRIME, XLE and Limited are 4 doors SKS which include the fuel port lock. If you find any information on the conversion, please let us know.

 

if history tells us anything, the harness is there, and you need antennae and maybe ecu

 

You are thinking that all the necessary hardware is in there and just needs a command to start working. If this is untrue, or you can't find the command, you could try transplanting a full set of hardware from a junker and then running the signal wires to the working lock in hope of slaving the new lock to a working one.

 

My history with Prii has mostly told me Toyota isn't prone to running many more wires than the trim level they are building will need.

On a couple of occasions, I've been motivated enough to pull the dash apart or fish through the firewall to add something that wasn't in my trim, but often I just reconsider the project at that point.

 

you could very well be right. someone added sks to the hatch and passenger door of a gen 2 or 3, and all the wires were there iirc. still a big job though, it is detailed here somewhere.

i seem to remember things like power mirrors and cruise, etc. where the wires were there, but i'm old and mostly senile

 

It's worth mentioning that the wiring diagram typically does show what wires are or aren't going to be there in a particular build. I've used this drawing as an example before:



You can see you'll have the wires with (*6) in a car with the Touch Tracer display, or the ones with (*7) in a car without, and the wires with (*8) if the car came with nav, or (*12) if the non-display radio, and so on, with the legend for the numbered *s being up in the top corner there.

The nice thing about that is you can find out what kind of a job you're in for before crawling into the car and pulling panels off.