Apologies for piling on, but the thread subject kind of asks for it...
Right around Thanksgiving, I bought a set of snow tires for my LEAF and had them mounted on their own rims. I'm not at all fond of the notion of $100/wheel government-mandated TMPSes, so I declined the tire shop's offer to have any of them installed in the snow wheels. A few weeks back, the weather forecasters thought we were in for a significant accumulation of snow (perhaps a couple inches!), so I decided to switch over to the snow wheels. I was prepared for some sort of pilotless State Security air-bot to come whizzing up and berate me over loudspeaker, or at least to see some flashing LED fireworks on the instrument panel due to the un-TPSed wheels, but.. nothing. I drove a few miles and back to a grocery store (after seeing to the car's mobility, the next priority was to make sure I had enough potato chips to tide me through the projected civilization-crippling blizzard) and no warning lights to be seen. Same story the next day on my 20-mile roundtrip commute: no warning indications on the dash at all. It was only on the day after THAT that I got the flashing stink-eye I'd been expecting. So I have a fair number of "idle curiosity" questions stacked up concerning the TPMS feature, and this seems as good a time/place as any to air them out:
Is it normal for the system to take two or three days (and about 25+ miles of driving) to notice the total lack of any pressure information received from the tires?
If so, of what use is the system to anyone except its manufacturer?
Or, if it's NOT normal for things to take so long, was the car's computer making a clever inference about the particular sequence of sensor readings? I mean, having all four sensors instantly (so far as the computer can tell) go from "in-spec" to "completely absent" might be taken as a clue that "maybe the owner is a cheapskate and swapped off all the wheels, so no point generating a low pressure false alarm". I kind of doubt it, because that would be a lot more sophisticated than the other bits of the car's user interface. But if it had made the clever inference, why'd it change its mind and go back to lighting up the "tire fault" warning?
I went looking through the owner's manual and the dashboard control screen for information pertaining to the tire status. It sure seems to me that if you've caved in to pressure from some government bureau and added several hundred dollars' worth of sensor electronics to the car for detecting any single one of its tires being at the wrong pressure, you'd at least want to present the sensor readings in some sort of system status screen somewhere. For Babbage's sake, wouldn't it be helpful to at least indicate WHICH tire(s) need looking at when they fault??? Is there such a status screen somewhere I didn't find (maybe it's filed under "Phone settings" or something...)??