I have the codes for the 4 tires, via Carista, but they give no indication of which code is for which tire. I guess I can put different inflation pressures in each tire, then see which code goes with each pressure, but do these codes make sense: 2A0A9B3 2A0A9BC 2A0A998 2A0A983 Thanks.
Those are the ID codes for the sensors - every sensor made has its own unique ID. Changing pressure at a single tire by at least 5 psi should show up on your scantool so you can match each ID with a particular position if you want. The scandata usually lists something like "ID1 - 2A0A9B3", "ID2-.." etc through all four sensors. The ID's for most cars are 1-LF, 2-RF, 3-RR, 4-LR. But that assumes that the locations are correctly programmed into the TPMS ecu. Posted via the PriusChat mobile app.
I've never seen a Toyota throw a code for a TPMS failure...even my daughters 2012 Sienna van, when a TPMS battery died, didn't throw a code (she just had the TPMS light)
Prius TPMS definitely has trouble codes to indicate failures. In Gen 3 they are in the C2 range, like C2121. I don't know what they are in the updated OBD specs for Gen 4. As for the four transmitter IDs, the system (at least as of Gen 3) has no idea which of ID1, ID2, ID3, ID4 is which corner of the car. Those are just four slots for remembering four transmitter IDs. You can remember which one is at which corner of the car, if you want, and remember to update your notes every time the tires are rotated. (Remembering that can also give you a stealth way of making sure a shop you went to for tire rotation actually did it. Stealthier even than smearing ice cream on one of the tires or what not.)
I assume you have gone through the procedure so that the vehicle relearns the new sensors? I switch to studded winter tires and I have to go through a procedure in the dash screen settings so the TPMS light doesn't come on. Immediately after doing so I also have to have the car relearn the tire pressure. This second step is NOT in the manual and if i don't do it the TPMS light will come on.