Evening, recently purchased A6 2018 2.0TDI and had the glow plug relay changed twice after the EML came on with the p0670 fault code. Clearly it's not two new relays, the fault once cleared comes back after about 3-4 engine starts which suggests it is an intermittent fault. The last autoelec that checked said all 4 Glow plugs are fine and also the GP fuse is GOOD changed the relay and light came back on😭. I'm thinking to get the GP fuse changed anyway not sure of location of the fuse if anyone knows the location? or any other suggestions would be greatly appreciated. 

Audi A6 SE 2.0 TDI 90ps 

38000mls 

If bought from a dealer within the first 30 days of sale then you're entitled to a full refund or for them to fix the car free of charge 

Outside of 30 days still under warranty (not a great one might I add) £40ph labour and upto £350 per claim 

Even though you're out of the 30 days you're still covered under the consumer law. If a fault occurs with a car or item in the first 6 months of purchase it is assumed the fault was there from when it was purchased. 

My brother is going through this now and getting his car fixed free of charge. It needed an abs pump (£3k bill!).