The air suspension pressure sensor monitors the pressure inside the air springs or central reservoir. The suspension computer uses this data to adjust ride height. When you load cargo into the vehicle, the height sensors detect the drop, and the computer monitors the pressure sensor while pumping air in to ensure the bags do not overpressurize. It also tracks reservoir pressure to cycle the compressor pump on and off.
If this sensor fails, it can send false readings to the computer. The computer may think the bags are empty and pump too much air in, popping the rubber bladder. More commonly, a sensor failure will trigger a suspension fault light and drop the system into a safe mode, disabling height adjustments.