TPMS. Tire Pressure Monitoring System. A federal requirement in cars after 2008. In the GT-R there is a sensor mounted to the valve stem that monitors air pressure within the run-flat tires. If you move tire locations, or swap to a different set of wheels, you may not be able to read the tire pressures, and you will likely have a warning light on the dashboard of the car. Up until now, the only proven option was to go to a Nissan dealer for them to reset the light. Some will do it for free, some charge for resetting the light. With the information posted by a member of NAGTROC, you should be able to reset the light yourself, with a relatively low priced tool.
Head over to the forum for the full procedure and pictures.