From my understanding of how the system works, which may not be 100%, it make sense that it came on after a fuel fill up as it would just have injected some more of the additive and that pushed it over the threshold for the warning to come on.
I have had the car quite a long time and this has come on in the past and I had the fluid topped up at a local independent Citroen specialist; I actually found the invoice for that work tucked in the front of the Haynes manual and it was 10 years ago at 110k miles, it is now up to 223k miles, so the fluid has lasted quite well.
Anyway, I thought I might try and do it myself this time. I have lexia so should be able to do the reset, I believe I have found the correct option on the "Diesel additive function" sub menu. But before that I need to actually get the fluid and put it in.
I have done some googling and read a number of posts on this forum, but from that my conclusion is there seems to be a number of options for which fluid it is supposed to be topped up with depending on exactly what model and age it is. So I was hoping one of the experts on here would be able to advice which type I need to get for mine.
It's a 2005 C4 2.0 HDI, the vin is VF7**************[VIN obfuscated, can be read by forum staff], I think it's a refillable tank, as I have a faint recollection of the garage mentioning that when they did it all those years ago, and the invoice mentioned 3L of fluid being used; but it would be nice to confirm that if anyone has done it themselves or has access to the docs.
Has anyone got any experience of doing it on this model? Can it be filled with the tank on the car, or does it have to be removed to fill it up. I have seen some youtube videos where they removed it but that wasn't for a C4 so not sure if this is slightly different.
Also how urgent is it to top up when the warning comes on? how much is left in the tank? From lexia I couldn't see any measurement of fluid volume, just a count of how many grams of additive had been injected, which in itself seems quite a low number if it has got through multiple litres of additive. I can only assume this figure is some sort of estimate for the weight of the active catalyst in the additive that has been used rather than the weight of the additive fluid itself?
