what do these buttons do

The one on the right is, as you guessed, to register the setpoint for the tire pressure monitoring system. User manual page 443. The warning comes on when the pressure fall below 75% to 80% of the set point. Some people inflate to higher than normal, and set the TPMS, so the warning will come on closer to what you want. i.e. if you usually run at 40psi, inflate to 44psi and set it; then the warning will come on at 36psi (instead of 32psi).

Have no clue about the left button. OBD port?

 

The other button is to disable/enable the pre-collision (pre-crash) sensor that retracts front seat belts, enhances braking, and applies the brakes when it senses that a front end crash is imminent. In the Gen 3, I believe it is only on the V and, possibly, only with the Advanced Technology package.

 

No, it's not the PCS disable; on cars that have PCS, it's to the right of the TPMS reset (in the picture, it would be on the other side of the nub that sticks out to the right of the button).
My car doesn't have it; does yours have any of the port-installed options, such as remote start or the security system? It doesn't look much like a factory-installed option, given that it's screwed in on a place where my car just has plastic (as opposed to a cover plate or at least screw holes, which would likely be present on a missing factory-installed option).

 

I don't have that button either. Could it be some theft deterent device installed by the dealership? Sometimes they pre-install these things and expect you to pay for them, when you don't, they sometimes leave them in the car, but they just don't activate them.

 

I agree with Tony. The button on the left was installed by the dealer or a previous owner.

Tom

 

As already stated the button you marked with the red arrow is the TPMS Set, if a car has PCS the PCS on/off button is the same kind of button but to the right of the steering column.

The button you marked with the blue arrow is not part of a normal Prius. There is a thread on here somewhere that talks about a tracking or locating device that some dealers put on new cars. They are usually removed before sale, maybe that is what the blue arrow points to? If I had one I would remove it and take it apart to see what is inside.

 

The OBD port is the white one next to the TPMS button.

 

if it's something like an anti theft device, and you have them remove it, make them replace the panel as well. I wouldn't want the empty holes there, personally.

 

If there was an alarm pre-installed then I think it's pretty safe to say it's left over from that. In fact, if it was pre-installed and you refused to buy it, I would suspect that they just left the whole thing in there and just didn't give you the fobs. I imagine it would cost them more to have someone remove it than the actual alarm system cost in the first place.

 

The one on the left is the cloaking button. It is used to run in true stealth mode. Nobody can see you or hear you coming. You can hide in plain sight....

 

The button next to the OBDII port is for the dealer installed keyless entry. A lot of the dealers have it installed aftermarket for cars on the lot so they can lock the keys inside the car and have one set of remotes issues to the Sales Reps, Porters, and techs. That way they don't have to have a lockbox for all the keys and they are less likely to get lost.

When I worked at the dealer they did this and I thought that it was a major theft risk to leave the keys in the car, but they have security cameras EVERYWHERE and if it does get stolen, they have insurance to cover it. This is why when I ordered my Prius I told them that it better not have that system installed in the car when I pick it up, I know how they are installed and it's not pretty...

 

OP: I can tell you it is the control for a KARR alarm system. I have one too and got "suckered" into buying it. Supposedly, it modifies the Toyota smart key system so the transmission signal from the fob cannot be "scanned" by a would-be car thief. The only other benefit is that a KARR system has a shatter sensor so if the car's windows are smashed, the alarm goes off.

On the more expensive KARR systems, there is a feature called TRAK where if you desire, you can monitor the movement of your Prius via GPS on a PC based system whether it's been stolen, or say your wife or kids are using it (big brother watching!)

 

It's probably a dealer alarm, well half of it anyway. I found one on my Infiniti. The other half is in the dealer somewhere. It's no good to you.