2008 Dodge Ram 2500 Pickup Owner Manual Diesel - Page 340

338 STARTING AND OPERATING TIRE PRESSURE MONITOR SYSTEM (TPMS) - IF EQUIPPED The Tire Pressure Monitoring System (TPMS) will warn the driver of a low tire pressure based on the vehicle recommended cold tire inflation placard pressure. The placard pressure is defined on the Tire and Loading Information label. The Tire and Loading Information label is located on the drivers side B-pillar. Vehicles equipped to be operated in either the "max load inflation pressure" condition described on the Tire and Loading Information label or the alternative "light load inflation pressure" condition described on the Supplemental Tire Pressure Information label, may also be equipped with a reset switch to choose the appropriate TPMS low pressure warning threshold levels based upon the vehicle load condition. The Supplemental Tire Pressure Information label is located on the rear face of the driver door. Operation of the "Light Load" reset switch is described later in this manual section. The tire pressure will vary with temperature by approximately 1 psi (6.9 kPa) for every 12°F (6.5°C). This means that when the outside temperature decreases, the tire pressure will decrease. Tire pressure should always be set based on cold inflation tire pressure. This is defined as the tire pressure after a vehicle has not been driven for more than 3 hours, or driven less than 1 mile after a 3 hour period. For information on how to properly inflate the vehicle's tires, refer to "Tire Pressure" under "Tires - General Information" in this section. The tire pressure will also increase as the vehicle is driven - this is normal and there should be no adjustment for this increased pressure. The TPM System will warn the driver of a low tire pressure if the tire pressure falls below the low pressure warning threshold for any reason, including low temperature effects, or natural pressure loss through the tire.