Screwed-up TPMS: Tell me how this makes sense

I agree about it being cost ineffective. What I understand about the way the Toyota TPMS sensors work (and cost) does not give me a warm fuzzy at all. This is something I don't need and would opt out of. Ditto for the wonky capacity reducing, random sized fuel bladder, and overly complex HID's (thankfully I don't have the latter.)

Give us better thermal management (thermostat controlled shutters on the grill for example), something that would improve both comfort and real world mileage. Give the inverter protection from a reversed polarity jump.

 

After reading 21 posts, allow me to chime in since I did some research myself into this topic.
Early models of Lexus relies on tire rpm (rotation per minute) to compare four tires (leverage on ABS sensors). That system is cheap and not reliable. My co-worker's LS430 has given him 2 false warnings. The dealer simply reset the light for him. It has been OK for a couple years now.
The new system uses FM-based emitter inside each tire. Simpler system has ONE receiver to receive signals from all four emitters. With this system, it does not tell you which tire has a low PSI. You need to find it out yourself. Most lower-end vehicle has this syetem. Most high-end models (such as Acura, Lexus, etc.) has a more complex system that can tell you which tire has the low PSI. This system has four receivers, each located near the tire (i.e. near wheel well). With such system, one needs to re-register the tire every time one do tire rotation. It is annoying if you like DIY. I guess high-end vehicle owners don't do DIY much, so it must be OK.

TPMS is now required. Some makers go cheap by using the tire rotation system. Others use the simply FM-based emitter.

Some questioned the possibility of confusion when two Prius parked side by side. The chance is very low since the IDs are entered into the ECU of TPMS. Unless two sensors have the exact IDs (which seem very unlikely), they don't confuse the ECU easily.

To conserve the battery (a small Li-Ion button battery) inside the emitter, the PSI is only measured once every certain period of time (say 30 minutes) and when the rotation reaches certain speed (15mph, for example, sensors can detect rotation roughly based on pressure). With this, the emitters can last for 10 years (life span). Therefore, your TPMS system only functions periodically, not constantly. This would explain some of the confusion since one usually assumes it should function continuously. No, it does not. The reason is to same emitter battery.

 

To conserve the battery (a small Li-Ion button battery) inside the emitter, the PSI is only measured once every certain period of time (say 30 minutes) and when the rotation reaches certain speed (15mph, for example, sensors can detect rotation roughly based on pressure). With this, the emitters can last for 10 years (life span). Therefore, your TPMS system only functions periodically, not constantly. This would explain some of the confusion since one usually assumes it should function continuously. No, it does not. The reason is to same emitter battery.[/quote]


What do you think about this. Here is the scenario: Car turned off, wheel off of the car to have new tire mounted. During the time the tire is off the wheel, and before the new tire is mounted and inflated, the sensor sends a signal which would normally tell the receiver that the tire is low. The next time the sensor sends a signal the tire is inflated and back on the car. When the car is truned back on, will all things be normal with the TPMS?