2023 Prius Prime SE - TPMS Schrader 33500 EZ

I think it's in the manual. There's a whole section on it with a lot of blah blah in it.
Here's only one page, for rotation.
I think it's needlessly complex.

 

The car can remember two sets of tyres. It is capable of detecting new sensors without special tools, but only they're if they're of the newer type.

From the "so long as they are programmed at installation" note, yours are presumably of the older type, which would mean it can't detect them from scratch.

Given that the car is apparently not listening to these sensors, your best hope is that installers DID program the codes in, as they were supposed to, but they helpfully programmed them into the blank spaces for the second set, rather than overwriting your initial set.

But they did that without actually selecting the second set, which you should be able to do now.

Procedure for that is in a page close to the one posted above - "Selecting wheel set". Menu entries TPWS Setting -> Tyre Set Switching -> Register Valve / ID -> Tyre Set X.

If you flip that, maybe it will start working. (After maybe 5 minutes of driving).

If not, try flipping back to the other set, and then try the rotation thing above.

Last resort before going back to the installers would be try a from-scratch registration as per the section "Registering ID codes", but I would not expect that to work with the sensors you have.

(And I would be concerned that using that menu entry would make it forget a sensor set, thus forcing you to go back to the dealer to reprogram the old-style ones. Take care not to use it on the old sensors' set when you get them working. But maybe it's sensible enough to not blank codes unless it sees some new codes to replace them with.).

Car Care Nut video about the two Toyota sensor systems, which may be helpful:

 

Watching video-it is 4 years old.
Brings back memories of the Ford Exploder.
edit: It looks like that Schrader needs a scan tool:
https://www.schradertpms.com/en/our-products/schrader-ez-sensor-familyr

Too bad, because non-OEM direct replacements are available.
This is what I came up on Amazon for a '25 Prius:

 

The "register new" option was my last option to try, which I thought could break it by forgetting any codes they did register.

Did you try the my option of the tyre set switch? Maybe that's what you meant.

The choices in the menu are really badly worded.

"Tyre Set Switching > Register New Valve / ID > Tyre Set X"

Identifies and registers new IDs for that set (requires new type valves)

"Tyre Set Switching > Register Valve / ID > Tyre Set X"

Looks for the old IDs for that set (hopefully works regardless of type if already registered)

"Tyre Rotation" presumably does the same thing as reselecting the current set.

Are you sure you can see pressures from the OBD? For you to be getting them from the car's but for the car not using them itself is weird. Does the OBD show you one or two sets of ID codes?

I don't know any special reset procedures. But I'd hope that the "Register New Valve / ID" would always work to get the original sensors back operational.

 

Are those pressure values actually updating? Could be last pressure seen from the old set, maybe?

Have you actually tried switching to the other tyre set? Your previous message sounded like you were trying to register new IDs, and you didn't respond last time I asked that.

Do you get a different set of ID codes shown if you do switch set?

Unfortunately, I don't really have any experience of debugging this sort of thing - someone who's grubbled in there more would likely be able to tell at a glance whether those IDs were the original Toyota ones or your replacements.

I think I'd just go back to your tyre place and don't leave until they get the TPMS you paid them for to work.

I don't see how they could possibly mess up the car's autosensing of the original set again.

Main problem you're going to always have a risk of hitting would be you losing the replacement set IDs again by not using the tyre set function properly, and overwriting their IDs with by doing "register new" of the original set on top of them.

But if you have that OBD scanner, could you not use it to reprogram the IDs yourself, once it's been established what they are?

 

In case "throwing in the towel" is an option: TPMS is not mandatory in Canada.

 

I'd go back to the tire place.
On a side note, that procedure in the manual is needlessly complex.
I wonder if you don't follow it to the letter you'll get those dashes?
I suppose you could see if the OBDC readings change overnight...
If they do, it means the car knows what they are, it's just not telling you, because it feels the data isn't of high enough quality, yet.

edit: Oh, and I just noticed that it's TPWS per Toyota, lol.

 

Canadian Tire sold you the sensors and you paid them to install them, if they can’t get them working it’d seem a refund is due. Yeah it should work, and apparently gen 5 can recognize two sets of sensors without (expensive) dealership intervention at every swap, if it’s not happening, refund is an option. The most expedient would be to just leave them installed after the refund, if they’re ok with that.

With our gen 3, which only recognizes one set of sensors at a time, when I go snow tires in November 2010, through a dealership, the mechanic came out and asked if I wanted sensors, while shaking his head no.

there’s an extra light on the dash for about 5 months, then I swap back to the all seasons, light goes out.

 

I think this might explain it. It seems they did register them as the second set, and they're working now after you switched set. The car is happy with the sensors, or the TPMS light would be on.

But I think the car is simply choosing not to display the pressure because it doesn't believe the absolute calibration for old sensors. It's reverted to the old style where it will just indicate a warning if it sees a 10% (or whatever) drop.

This would be confirmed if you can see that the option to set a particular absolute pressure is unavailable, and it'll only let you set current pressure.

If you've got a tyre pump to hand to reinflate, you should be able to confirm that they're working by deflating one, and seeing if it lights the light, and indicates the offending wheel.

I can believe that the actual message you're seeing is misleading, like the other wonky text in the whole UI system. Dodgy Japanese->English translation, maybe not recognising full context of messages? But the TPMS light itself absolutely should be on if the system wasn't working - that's a tight legal requirement.

(Presumably the TPMS light wasn't on when you picked it up because it could still get signals from the other set, and it would take a little time of them being far enough away to decide they were definitely gone.)