Low Fuel Pressure Detected - Diesel

[angryengineer]

Dear Forum,

I really need advice, and thoughts are very much welcomed, from those with mechanical experience & with a minute to spare.

I have a 2005 registration Corolla 1.4 D4D saloon with mileage at ~155,000. The car is well cared for.

I get an intermittent engine warning light, with the code indicating the detection of low fuel pressure. The engine oil (100% synthetic), engine oil filter, engine air filter, engine fuel filter, and cabin air filter are replaced methodically every year with either mann or Mahle branded replacements. I have never used any other manufacturer branded filters in the car. Electronic parts that required replacement were always of either Denso or NGK brands.

1. What do I need to do to fix this warning light from appearing? Is the diesel fuel pump located in the diesel fuel tank and is it known to fail like this?

2. Do I need to drain & clean out the fuel tank of possible residues/sediments that have built up within over the years?

3. Are the fuel lines made of metal/rubber/braided rubber/or something else and can a tool be purchased/obtained to clean their internals out?

4. What are the identification names of the the fuel lines circulating fuel (a) from the fuel tank to the fuel filter, (b) from the fuel filter to the engine, and (c) circulating excess fuel back again to the fuel tank? By identification names what I mean is the identity names that a dealer or motor spares shop would know exactly what I am requesting.

My mechanic will be doing this work for me, however I want to be clear in my own mind what he will be doing.

If necessary I want to be able to direct him to do a bit of extra work, thus ensuring not to have to come back to treat another aspect of the same problem again in the future. I'd rather spend the money now and get it over with, fully. My mechanic is possibly a little less scrupulous and thorough going than I tend to be! 😂