As to why you would get a false warning I don't know. However our TPMS is not the type that directly measures tire pressure using sensors, instead when you calibrate it measures each tire's rotational speed, then if a tire later loses pressure the rotational speed changes and that triggers the TPMS warning. The drawback is it won't display the actual pressures on the screen, but the advantage is lower cost, not just for Honda but also for us as sensors are expensive to replace and they also make changing tires or fixing flats more complicated because the repair person has to be careful not to damage the sensors. Whether these type of systems are more prone to error than the ones with sensors I don't know.
I wonder which is better - GM's solution with a sensor in each wheel or Honda's that measures rotational speed. Dealing with both I think I prefer the sensor in each wheel because I can check the tire pressures while driving. It does add some hardware complexity to the system because you need a receiver for the sensors. On the other hand, using the ABS system to measure wheel spin speed reduces the amount of hardware needed and allows you to more easily do things like change rims for the winter, wheel sizes, etc.
Sounds like something is causing the rotational speed sensor to error.
