Why is the tire pressure light on in my 2006 nissan Frontier truck , if the tires are full?

um u mean they are at the right pressure???......size has nothing to do with the light...... sometimes light will come on with temp changes....so u may need to let some air out of tire and tehn refill them to correct pressure........or as we used to do in tire shop just add a couple pounds to each tire and that usually makes light go off..... btw the light may be on becuase the battery in the sensor is dead......they only last around 5 years max.....so u may need to buy new sensors.....walmart seems to b the cheapest installed......good luck also tire shop can check to see if ur sensors are good.....

Were they low and the low pressure light on and you filled them? Or did ths happen all of a sudden. Double check your pressure when warm, and make sure they are the correct pressure that is indicated in your owners manual or on the inside of the drivers door jam. Also check the manual and see if there is a restet procedure. Check the doc below and see if it helps any. Good luck.