Hello,
I have having a problem with the tire pressure light for my 2006 Nissan Quest. I lost the cap for a while, and the light kept blinking that that tire was unreadable. I got another cap from the dealer and it still keeps blinking. It is driving me crazy!
Please advise.

Is there anything in the owners manual. (allot of people will not look)
If that doesn't help, you can do one of two things pat the dealer, to fix it.
Or put a piece of black tape over the light.

I think you may have a low tire. Are they all set about 32-35psi? Even the spare? (if it's a full size tire)
Have you reset the light using the reset switch? Owners manual is a big help here and must follow it step by step.
Other than that, a scan tool is needed here to look at all the sensors and read their pressures and temps.
I see a lot that read minus 40 degrees, and zero pressure. Of course that means it's dead and needs replacing.
They aren't cheap and must be handled with care when replacing tires. Have you had tires replaced?
Yes they drive people crazy, but it's great warning light to have for safety reasons.
No one seems to watch tire pressures nowadays. At least this little device does.
Remember Explorers with Firestone tire issues?

I have a 2005 nissan quest, I had a nail in my tire and the light went on, I got the tire plugged up and it still stayed on, I have since got brand new tires and the light is still on, the place that put my tires on said it was the sensor in the tire that had to be replaced by the dealer in order for the light to go out, you may want to have the sensor checked. Hope that helps. I still have not had mine fixed.