Does not start

Do you have any codes? check with code reader not all code set a check light. do you have spark? did you do the head gasket and was this a recent problem, is it not starting since doing the head gasket?

complaint code u0008.,u003

Those are communication codes so one of the computers is not talking for some reason. I would start by checking all system fuses. If one of the computers is not getting power it will cause this error.

Here is a guide and some diagrams of the fuse box (below) so you can do some testing.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Please check all system fuses with the key "on"

Please run this test and get back to us.

Cheers, Ken

sir,all wiring harness replaced,rail with sensor,h p pump and cylinder head ,Ecm also.. ....
but engine starting few times(10 second)also.this time
engine dtc check no trouble code,engine again start not starting and dtc check U0003,and U0018,some time U0008 .

sir no replace parts this category .only balance for engine block,timing belt

All communication errors. Please check for power at each of the fuses and make sure the relays are working. If everything checks out check the power and grounds at the computers because something is not working or powering up. This car is diesel correct?

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Please let us know what happens.

Cheers, Ken