Depollution system faulty. How can I fix this?

I have a peugeot 207 1.6 HDI. The other day I very nearly ran out of fuel and only just made it to petrol station. Just before I pulled up the engine cut off but was able to coast to pump. After filling up the Depollution system faulty message came on. I am having no other problem as the car is running just fine. Been like this for a couple of days. Is this something I should worry about or can I wait until my regular service in about months time.

Rob
August 2009