Flashing glow plug light and ECU light constant

[gsh72]

Hi all, not sure if this post has been made before by someone else, I did look and couldn't find anything so apologies in advance if I missed it.

I bought a 58 plate 2.0TDi Passat about 6 months ago with 85k on the clock, 1 previous owner, and a full VW service history. Today the glow plug light came on and started flashing, quickly followed by the engine management light which is constantly on. The little screen also says 'Engine Fault, Garage!' There doesn't seem to be any loss in power though I was only a mile away from home.

I'm not knowledgeable about these things so could someone give me any pointers as to what it could be so I could prepare my wallet for battering.

Thanks in advance.