SKS system nonfunctional

New here!
Just bought a used 2005 Prius a couple weeks ago. Upon purchasing the car the transponder body was In a pretty bad shape. No coverings over the buttons and some corrosion, but it still worked. Replaced the body, and the first day it continued to work. Roommate took it to the gym. Came out from a workout, and the fob no longer functioned. He mentioned that he dropped it.

The same night I replaced the battery I added an Aux input to the radio. (The aux input didn’t function, but I left it in there in frustration...)

We have to use the metal manual key to unlock the car, and it does start with the transponder inserted.

So far we have taken the transponder body apart to confirm that it is correctly put together.
Issue persisted.

Battery tests at 12.4V in ACC mode using onboard diagnostics.

Tried the transponder in original housing.
Issue persists.

Cleaned transponder using a small brush and 100 proof alcohol prep pads to remove corrosion.
Issue persisted.

Removed non-functional AUX input add on, and plugged in Toyota 6-disc add on.
Issue persisted

Attempted to reset 12v battery by removing the ground connection connected to the body of the car in boot area. Kept ground connection removed for a minute.
Issue persisted.

I will add that the radio presets did not reset, so maybe remove ground for longer?

Took the car to an auto parts store to have 12v tested.
Tested at 12.43 in ACC mode.
Tested 14.7 in ready mode.

I will say that there is a usb plug-in in the accessory port. Green light turns off when car is off.

Plan to remove USB plug-in and leave ground unconnected for a while.

Any other suggestions?

Plan to contact a few Prius repair shops and dealerships to get transponder quotes.

I know that I can order the cord and software online, but I don’t have a windows laptop...

Must admit that I was, embarrassingly enough, seated on a metal stool with rubber/plastic on legs. Maybe between the corrosion and possible ESD damage the transponder just needs replaced?

 

Also the on board diagnostics read the 12v at 11.5v after the car remained off for 30 minutes.

 

Remembered the rFID chip.

 

No wires were modified... just unplugged the 6-disc Toyota add on, and plugged in the aux input....

 

So the holidays kind of took hold of everything. Replaced the 12v battery, and issue is resolved.

in the process of replacing the 12v battery I discovered that the battery didn’t have a vent attached, so now I’m going to have to find a vent tub for it. Also discovered that hybrid fan vent isn’t bolted down in any manner at all.

Love the car, but it seems as though the previous owner did a lot of interesting work on the car.