I recently returned from a 700 mile road trip up into the mountains in the eastern US and found that my 2008 LR2 HSE (petrol) was sporting a jaunty yellow CEL. I popped in the OBD reader (ELM327 via Torque Android App) and it spat out the following code:
P2404 - Evaporative Emission System Leak Detect Pump Sensor Circuit High Range/Performance.

There is surprisingly little information to be gleaned from the Almighty Google, so I put the question to you kind folk... what gives?

It's still under the extended warranty, so I will likely just schedule a service visit tomorrow, but I'd like to understand my vehicle a bit...

Edit: FWIW, the light has been on for a few days. I have verified the gas cap is secured (I would have felt quite the **** if that had been it), and I've about a half a tank in the vehicle.