It's more unusual to not see P0380 on these. So common it doesn't even put the MIL on.
They don't use the glow-plugs at all to start unless it's very cold; but run them for about three minutes post-start for emissions reasons. That's why they've nearly always got at least one plug burned-out and often a cooked relay too.
Check cranking speed and rail pressure in live-data when it won't start; you need at least 300 revs and 120 bar before the ECU will even get interested in firing the injectors. It also needs to see cam/crank synch - belt loose?
If the rail pressure is low, do that leak-off test; also ask the owner if it's even been mis-fuelled or run on "bio-diesel..?" If so remove the filter and check for steel frag.... If found; do not refit the filter - change the whole filter housing and tell him he needs a mortgage....
If it has bad compressions, it will spew clouds of white smoke on cranking - does it?