Tires...TPMS...Do the tire sensors have to be "rebuilt" or "cleaned" when changing tires?

How do I "Press the reset button"? I've adjusted the air in my tires a few times and never reset anything?

 

I'm still confused. The pics shown make it seem like the sensor is part of the valve, (big black rectangle on the wheel side of the valve). Yet descriptions say it is not.

If you don't care about TPMS working, can you just have them put standard valves, then either use the reset or remove the bulb in the dash? (Assuming it's a bulb and not some other device that lights that up).

 

The warning light is an LED built-into the console. Black tape would be your best "fix" to disable it. The light will go on if it doesn't see one of the transmitters, so there's no way to remove one without setting the light.

If you are not changing the set pressure of any of your tires (just refilling them to the original pressure), you do not need to reset the TPMS. The TPMS warning goes off if a tire loses 25% or more from its set pressure. If you increase the tire pressure without resetting it (ie, going from 32 to 40) you will have to lose more air before the warning goes off.

The TPMS transmitter is built into the valve stem -- they're replaced as a unit.

The Prius only has 4 sensors -- the spare does not have one.

 

Thanks for all that detail. So about the only thing you did not include is, does the transmitter/valve stem have to be replaced when changing tires?

 

As a newbie, this is confusing to me. Days after i got my prius last month, i got a new set of tires, installed at Discount Tire. I then read on this list that the sensors are in the valves, and that they shouldn't be removed. On my invoice from the tires there was a charge for new valves. This really worried me. To confuse myself more i got a tire pressure gauge that didn't work very well, really hard to get a seal, widely different readings at different times, my own lack of knowledge about tire pressure, i thought my sensors were toasted.

I now have learned that the valves have a core and a stem (and maybe other parts, i'm not sure) and that the sensors are on the stem (? i think) and that the cores can be replaced without damaging the sensor system, and apparently Discount Tire only replaced the cores on mine.

I think the answer is, no you don't need to change the valves when you change tires, as long as they are in good condition. I'm not sure if that means both the core and the stems, but if you need to change the part with the sensors, that is really expensive, compared to just the cores which is $2 each or something.

On my invoice it said "replaced valve stems," and on Prius Chat, i learned that the sensors were in the stems, so this did freak me out. but now i understand all is well. Just an ambiguity/error/misnomer on the invoice.

 

Tire shops do that. It's just another way to cheat you out of a few bucks. They don't replace the stems because the stems are part of the sensor unit, but they charge you anyway unless you complain.

To answer a previous question, no, you don't replace the stem units when you change tires. They are very expensive, and it requires a trip to the dealer to pair them with the car.

Tom