Tyre Pressure Monitor

[TheFly]

I've only had my Audi for 2 months so please excuse my newbie question. My tire pressure light went on today. Would 28 degree weather cause this?

Not that it means anything but during a visual inspection none of my tires look low at all? Just wondering how sensitive the pressure monitor is?

[elwigglero]

Check the tire pressure...using a gauge. Fill with air.

[Great White]

I've only had my Audi for 2 months so please excuse my newbie question. My tire pressure light went on today. Would 28 degree weather cause this?

Not that it means anything but during a visual inspection none of my tires look low at all? Just wondering how sensitive the pressure monitor is?

This happened with me before and again 2 days ago when it started to get cold.

Like elwigglero said, fill with air (default is 36psi) and you may need to reset the computer. Check the owner's manual, it describes in detail how to do it.

I considered fill my tires with Nitrogen, I'm sure AZ will have an opinion on the matter ;-) Let's hear it.

[minameismud]

Yes, when it gets cold, anything filled with air will "lose" pressure. No air has escaped (unless you've got a leak), it's just the laws of thermodynamics in effect. Check out the Ideal Gas Law. If the temperature goes down, so does the pressure. This is the same concept behind telling people to only fill their tires and check the pressure when the tires are cold (ie. not driven on). So, if you get the TPMS warning, break out your pressure gauge, figure out which tires are low, and fill them to the recommended pressure as listed on the back of the driver's door frame (below the latch). You're supposed to check your pressures regularly anyway, as tires naturally lose air over time (hence filling with pure nitrogen - it leaks through the rubber slower because the molecules are bigger).