First 2 days after installing new winter tires no TPMS warning light. Then today the light went on but tires look fine. Car was outside 7C. Not sure if winter tires have TPMS sensors (Michelin Ice -X).
Well the sensors are inside the rims and communicate with the car. I suspect you took a longer drive today so that's why the TPMS light came on. If you have your factory tyres stored near your car (in the garage or if you live in the townhouse/condo, in the storage locker very close to your car), the car will read the sensors of your factory tyres and the light will stay off. But if you drive long enough that it no longer can read the sensor (or if your factory tyres are stored elsewhere), then the light will stay on for the rest of the season. I highly doubt your winter tyres have sensors as they are an extra cost to install and you have to get them to reprogram it twice a year (Toyota only installed enough memory to store 4 sensors rather than 8 so that's why you have to reprogram them to the new set each time you swap tyres).
TPMS is not mandatory in Canada. Yeah you very likely just have plain valves. You might count your blessings: Toyota’s system, unless you invest in know-how and pricey electronic devices, requires pro intervention with each swap. If you want to DIY the swap, that’s a significant (and expensive) impediment. I would just carry on; the light’ll go out next spring.
You did not say if 7C temperature was below where it had been the first 2 days, but a drop in temperature will reduce the pressure in the tires and it may have been enough to trigger the warning light. At this point you should simply check the pressures in all tires, set them where you want them and then reset the TPMS. It's likely it was not reset when winter tires were mounted and maybe the winter tires were not set at the same pressure as the ones replaced.
They may look fine but what is the pressure? A temperature change can change the tire pressure or there's a slow leak that isn't noticeable yet. Is the light turning on and staying on or is it blinking for a while then staying on? If it comes on and stays on without blinking your pressure is off you just need to add air to the proper pressure then reset tpms. If it's blinking for a while before staying on there's a problem with your sensors and you'll want to bring it back to the dealer to fix. They could have knocked one loose or it's battery died. If you swapped rims and tires your car might not be set up with the new sensors in your new wheels or the new wheels don't have any installed. If you park in the garage you may still be close enough the car is reading the sensors in your summer tires but then you leave and they get out of range
If the light comes on and stays lit, that means the problem is TPMS itself, that is the system is not working. Low tire pressure warning when TPMS is working correctly will warn with flashing TPMS light. This is most likely because you don't have a TPMS sensor in your winter tire set. Unless you swapped tires onto the same OEM rims, you have to purchase an extra set of TPMS sensors for the winter tires/rims to have functional TPMS.
Mazda vehicles have similar system, TPMS sensors incorporated into each tire valve. With their system, if owners have an extra set of tires/rims with sensors, after a DIY swap the only action required is: (Excerpt from CDN 2018 Mazda CX-5 Owner's Manual.) Also, I checked prices for sensor, through an online Canadian Mazda dealership back east: $30 CDN apiece, with shipping IIRC.
The pressure sensors Discount Tire put into my snow wheels requires reprogramming with every change. It just takes a few minutes, no charge, and they're always nice about it. They claim that one programming should work without re-doing it, but that's how mine work. Other cars I've had needed only the initial programming for snow wheels.
The tires don't have sensors, only valves have sensors. Valves go with the rims. As others already asked, what are the measured pressures? Visual checks are not good enough. After determining that pressures are good (and if needing to add air, you've given them 10-20 continuous driving minutes to catch up and clear any alerts) ... Are these new tires on the original factory rims, or on separate rims? * If factory rims, then the shop messed up the one or more TPMS sensors. Go back and have them fix it. * If new rims, then look at your sale invoice, it will show whether or not you were charged for new TPMS sensors too. ... ** If you were charged for new sensors, then the installers messed up (e.g. didn't install, or didn't program, or broke something). Go back and have them fix it. ** If you were not charged for new sensors, then you don't have them. Either ignore the light all winter, or cover the light with black tape. Or ... *** Unless you want functioning TPMS, in which case you'll need to go back to the shop, buy new sensors, and have them installed too. If this were in the U.S., the labor to install them should be free, as it was illegal for the shop to not install them the first time. (Shop will still charge for parts.) But since Canada doesn't require the sensors, the shop might get away with a new labor charge to install the sensors.
Quick tip if you have winter tires and you have to do a state inspection. Vermont used to fail the car if the TPMS light was on, even it was because you were using your winter wheels without the TPMS valves. To "fix" the problem I would have to load the summer tires in the car when I had it inspected. Light goes off and the car passes. Dumb rule for sure! Eventually they changed the rules so the car could pass with a warning.
This was more for other folks who run into this "problem." It sounds like Canada is more reasonable on the inspections. Point to Canada
Thanks to all. Winter tires brand new, part of purchase deal. The rims are ‘Corolla rims’ as per the contract. I’m sure you’re right that TPMS sensors were not included. Nonetheless I will check the pressure and check with Toyota to verify. I had the same issue with my 2012 Prius. Thought in 9 years this would be resolved! Btw, the light blinks for a while and then goes solid. Thanks again.
