TD4 failing to start ? Check and replace this fuel pressure regulator sensor seal.
Such a tiny green seal stopping the whole engine from starting.
Buy this one as it has the better quality green nitrile? seal not the cheaper black ones. It comes with the support split washer and gasket.
Expensive for what it is, but you can't use the vehicle without it. But do also check your engine camshaft sensor as this will also cause the same non code causing failure to start condition. Fiddly to fit but fairly simple, remove the inlet manifold and remove the sensor plug. Make sure it is refitted square and evenly wound in.
You may find your inlet manifold and exhaust gas recirulation system is bunged up so maybe expect to clean that out while it's apart. Help your engine to breath again. Sorted.