Think something happened to a tire sensor. Dashboard light went on. Tire pressure on all tires is solid. 2012 Prius PIP. Thinking a tire sensor went bad. - Is this something someone reasonably handy can replace (w/o the hassle of removing a wheel or tire?) - What do they normally run Recommendations on replacement brand/part/store? Links? - Prius do for oil change and rotation, thinking of having service shop get it but do not want to fleeced on price. Think if I supply the sensor they might install at a more reasonable rate.
They are battery powered, thus finite life. They can be replaced without fully dismounting the tire, but it will have to be deflated, and the bead seal broken, to remove and replace the sensor inside the rim. Consider changing all four.
I’d do nothing until the next time you’re getting new tires. Unless you’re in a State with inspections that would pull you off the road.
Any way to tell which sensor might have gone bad? My BlueDriver scan tool provides no information on the tire pressure sensors.
Each sensor has an ID number (printed on the sensor—you can't see it when the tire's on the wheel). The car's TPMS computer has 'slots' to remember the ID numbers of four sensors. The slots are called ID1, ID2, ID3, and (wait for it) ID4. At the factory, the IDs of the four sensors were programmed into those slots. (Techstream and some other scan tools can do that.) The particular trouble code being reported by the TPMS tells you which ID slot it means. For example, C2121 means no signal from transmitter ID1, and C2124 means no signal from transmitter ID4. Without a scan tool, you can get the trouble code using the light-blink method. But that only tells you which ID slot. You don't know which transmitter ID number is programmed into that slot, unless you used Techstream or another scan tool one day to retrieve that list and you saved it. If you did, you can look there to see which transmitter ID is in that slot. Even with that, you still don't know which corner of the car to go to, unless you have been keeping a list of which transmitter ID is in which tire (at which corner of the car, and rearranging that list at every tire rotation). If you have been doing that, then, yes, you can tell which tire it is. Right about now, you probably won't be surprised that tire shops use special wands they can just wave near the tire and it picks up the transmission and tells you which ID number is in there. Or, if it doesn't pick up any signal, you've found the one that's stopped transmitting. But sometimes, in that case, the wand will pick up one of the other nearby tires instead. So instead of getting a list of three IDs and one no-reading, you'll get a list of four IDs, but they won't all be different. There's the giveaway.
You can buy an Autel Tire TPMS scan tool (~$150). Note, there are cheaper TPMS scan tools. Autel also sells their own fully programmable TPMS (sensors). They are ~$30 each, and require an Autel TPMS scammer/programmer. That's what I use. I now have Three complete sets of 4 tires each. 1) The original "okay" Bridgestone tires. 2) My new Michelin Primacy A/S (LRR) tires on separate rims. (Rush hour traffic sucks. Imho, I want the "best" appropriate tires on my car, for best stopping/road/etc performance - during all types of weather.) 3) My **REQUIRED** Blizzak snow tires on separate rims. (Don't leave home during snow season, without them! ) My two new tire sets have the Autel programmable TPMS sensors. The new Autel TPMS sensors are programmed to the same original corresponding wheel TPMS IDs. That way, I can swap tires anytime I want. And, I can accurately track, and document (via pictures ), the tire rotations and usage. The tire rotations are required by my stock warranty, and my (bought) Toyota 10-year extended warranty. If desired, I can also run Blizzaks up front, and my Michelin Primacy A/S tires in the back. If needed, I can put my rear Blizzaks on the back, because of upcoming/existing weather/conditions. And, not worry about the car's Tire Pressure warning system, nor having to do any OBD-II programming of TPMS IDs. This is my plan this winter, based on the snow so far this year, the ~3 month longer-range Winter forecast, and my likely travel/work(on site) requirements. Note, all tires are 195/65/15, on Gen4 Prius stock OEM 15" rims. And, of course, balanced (by a local pro tire shop). By using the Autel programmable TPMS (sensors), I also do not have to go through the semi-hassle of connecting up an appropriate OBD-II scan tool/programmer, and program in a unique TPMS ID for each tire, for every time I swap tires.
Certain TPMS tools can check the battery health on the sensors by bringing the tool up to the tire valve. My personal unit is an Autel MaxiTPMS ITS600. (There are various others though I'm not familiar with which is the cheapest option).