When the temps dropped here, mine alarm did sound off. Truth is, the tire pressure DID drop enough to trigger the alarm. The system DOES work.

I hopped in my vehicle and was backing out when it went off. I stepped out, checked all the tires visually, and deemed them safe enough to drive to work. I started the X once again, and the alarm DID NOT sound a second time, just an idiot light warning me.

Once I arrived at work, I parked it, went inside until lunch time. I took it to the nearby gas station to fill up the tires. Again, the alarm did not sound, just the idiot light again. I filled my tires up to 35 PSI, and once I drove off, the system reset.

So... if you do have it go off, it'll only sound the one time. The idiot light will stay on until you pump 'em back up to 35 PSI. No need to remove any fuses, it won't sound again. If it does go off, check your tires... it ain't kidding, you have a low one.

Since I filled up my tires to 35 PSI, our Temp swings 80s during the day, 40s some nights, it has not gone off again.

I give it

On edit: The valvestems are made by Schrader, not some fly by night company. Their literature says they are rated for 150K miles and/or 10 years. Since all SUVs will be required to have a monitoring system starting 2006, whatever you buy will likely have it anyway (see quote below). Furthermore, with SO many vehicles having this, the prices of replacement valves will significantly drop.

In April 2005, NHTSA issued a rule requiring automakers to install systems in all new passenger cars and trucks by the 2008 model year, beginning a phase-in with 2006 model year vehicles.