The same thing routinely happens to me. I've got my tires at 35-36 psi, however on a cold morning my low pressure light will still come on. As soon as the tires warm up a bit, the warning light will go off.
It seems to me that the tire pressure sensors are a little too sensitive to pressure variations due to temperature changes.
__________________
H3 Boulder Gray - 2006 Adventure|CD-MP3|XM|Roof Marker Lights|Husky Front Mudflaps|Brush Guard|Rocker Bars|UC Protection|U-Steps|Garmin GPS|Garvin Roof Rack|DVD Headrests|
|