Engine Warning Light --> low fuel pressure

[angryengineer]

Dear Forum 🙂,

I own a 2005 registration Toyota Corolla 1.4 D4D saloon. Mileage is ~155,000 miles.

I irregularly get an engine warning light when the fuel low warning light in on i.e. when the fuel content in the fuel tank is <= 15 liters. The engine warning light disappears a few days after filling up the fuel tank again.

The warning code is for low fuel pressure.

The diesel fuel filter is replaced religiously every year at service time with a new Mahle fuel filter.

What do I need to do to fix this warning light from appearing?

Do I need to drain and clean out the fuel tank of residues and sediments that have built up inside it over the years? If so, does the fuel tank need to be removed and washed out with something? Is this a difficult expensive job?

Should I treat the fuel system for algae/diesel bug?

Advice and thoughts are much welcomed.