The EAS Dryer is an essential and often overlooked EAS component. The primary function of the EAS dryer is to absorb moisture from the compressed air in the EAS system. A potentially bad situation could arrise if moisture contained within the compressed air froze or corroded metalic components. This is not a huge issue for drier climates but the vehicle was designed in the United Kingdom and I hear it gets wet there sometimes.
The EAS Dryer is connected to the high pressure tank through a Non-return check valve and the oring fittings should be checked when hunting down slow leaks.
Read and clear this fault code yourself with the EAS Unlock V4 for the P38 Range Rover.