The RL features a ‘Tire Pressure Monitoring System,’ or TPMS that displays the current pressure for each tire and warns the driver if a tire is significantly below recommended pressure levels. Pressure sensors within the valve’s stem of each tire transmit pressure readings to the systems monitor, which then relays the information to the multi information display. Please note that the spare tire is not monitored by TPMS. If the air pressure of any tire varies significantly below the recommended level, the system will alert you with this light on the dash and through the multi information display. This system also allows each tires pressure to be checked from inside the car. To view the tire pressure readings, turn the ignition on then press the information up or down arrow buttons on the lower right side of the steering wheel and scroll through the menus until you come to the tire pressure monitoring display. Then press the select/reset button. Through the display, you can view a current air pressure reading for each tire. For optimal tire wear and performance, tire pressure should be checked regularly with a gauge, Do not rely solely on the monitoring system.