136 OPERATION TIRE PRESSURE CONTROL SYSTEM (IF EQUIPPED) The Dana® Tire Pressure Control System (TPCS) is an incredibly simple system to operate. All commands to adjust tire pressures are controlled by the driver from an easy-to-use operator control panel located in the overhead compartment above the driver. The driver simply selects the desired mode with the touch of a button and the Dana TPCS does the rest, adjusting tire pressures to match the road surface. Indicators on the control panel tell the driver what’s happening. A built-in indicator warns the driver when he is traveling too fast for selected tire pressures, and the system logic automatically selects the appropriate pressure if the speed is not reduced. A warning icon also tells the driver to check his tires if the system senses conditions which may indicate tire damage. A pressure switch acts as an electronic brake priority switch to prevent the Dana TPCS from using air until the brake system is fully charged. Brakes always have priority. With its two modes of operation (Loaded/Unloaded) and three terrain settings, you get six pressures from which to effectively operate across a wide variety of terrain. "Highway" mode allows for high speed travel on paved surfaces, "Off Highway" permits operation on secondary roads, and "Emergency" provides extremely low tire pressures to help free a stuck vehicle, or take on grades that previously were impossible to negotiate without assistance. Plus, the Dana TPCS has various digital display codes that report when a problem exists, and exactly what the problem is so you know just what to do to correct the situation. The Dana TPCS requires a constant supply of clean dry air. An adequately sized and maintained air dryer is critical for continued proper operation of the Tire Pressure Control System. Even though the air dryer may be working properly, moisture can accumulate in the wet tank during normal operation due to the increase in air consumption. It is important to drain the wet tank daily. Draining the wet tank completely (to 0 pressure) when the truck is not in use will help keep moisture under control.