A couple of days ago I started getting a warning that I needed to check the tire(s) pressure. The message appeared in the instrument cluster and shows the pressure for all four tires. The posted "cold" pressure is shown as 29psi for all 4 tires (on gas cap door). And that is the pressure showing in the instrument cluster. So why the warning? Also, the instrument cluster warning shows all four tires, but only the left front is shown in a different color. I can find nothing in the manual to explain this. And 29psi seems low to me. Any thoughts?