[SidwaySRT]

Hey guys, hopefully someone can help explain this to me:

Driving home from the NAIAS (Detroit auto show) last week on the 401 in Canada (crusing at 90). I see literally "piles of scrap metal" in the left lane. I swerve right, i swerve left. I missed em phew.

Car in front of me runs over one and it flys at my right front valence/tire. I run over it and immediately think i busted my foglight/slashed my tire. I cut over into the right lane and slow down and bring up the tire pressure monitor. It's holding at 31 and car is riding fine.

Suddently it drops to "0". I pull over immediately and stop car. Inspect all tires and they are fine. Shut off car, still says 0. I knew that if the tires were rotated and sensor not changed it could be one of my others so i check them all. After im freaked and have no other choice (its snowing/9 degrees/no spare) I drive off and within a minute the pressure jumps back to 31!

What gives???

Is there something in the way they operate that could make them temporalily hit zero in response to force/bumping?

thanks for any and all insight! Gavin