'99 - 2.0 Exclusive Hdi engine auto-diagnosis warning lamp

[Edhertz]

Has anyone had the engine auto-diagnosis warning lamp come on after renewing the seal on the fuel sender unit? The lamp came on after approx 50 miles with no loss in performance ie normal running and no loss of power. The light flashes off momentarily on start up but then stays on. The fuel line has been vented so chances are there is not a flow problem. I will add that I dosed the full tank with Redex diesel fuel treatment which I had left over from my ZX Volcane. Any advice always appreciated.