Oil light comes on if at first i start again it will go off then ok

What weight of oil did you have put in the engine?

My truck Hino dutro year 2005 is on check engine light, coputer say this fault, p2002 particulate trap efficiency below threshold (bank 1) now i dont know what is this fault Plz send me detail for this fault and solution.

i think so that ur oil engine tank is leaked or remove from its place son check it
ok

some cars with oil level warning light on, it doesn't mean that its only reading the engine oil level is low, sometime the transmission fuid too. Did you check your transmission fluid if it is ok or not? try to check and let us know, ok.

check or change the oil level switch located in the oil pan area its just faulty

First - did you use the correct viscosity - SAE spec ?
Using a thiner oil can affect oil pressures.
Presuming that you did, and oil levels are ok, then I would check if this is a standard service light come one. They are programmed to light after a certain milage since the last change - and this seems likely if you have just done it (before light came on to remind you)

Try resetting it. This works for most models -
Turn ignition on - so you get display/ lights etc.
Set trip meter to show milage.
Turn ignition off.
Press trip meter button - and keep pressing it while turning ignition to on again.
Light should blink and go out.
Take finger off trip meter.
Depending on model - you may get some figures - 1200 , 800 , etc. This alows you to change service interval if you want - but if not - then just turn ignition off again.
Light should stay off.

If this doesn't solve it, I'll look for specific info of how to do it - or start checking other possible causes to check.

Check battery cables make sure clean ground to chassis from batt.

Change the oil! The 318Cu in V8 (5.2 liter) engine has a problem with sludge build up on the oil pump pickup tube screen. This engine requires oil changes at or before 3500 miles with a high detergent oil.

It might be faulty oil pressure sensor or bad oil pump, but might be adressed to recent oil change. Sometimes oil get viscouse in winter and cause oil light to come on. For winter the recommended one is 5W-30
Oil light should come on for less then a second during starting the car. If it comes longer or when you push the brake it might be the sign of bad oil (sometimes), faulty oil pressure sensor (mosty), bad oil pump (often) or internal engine problem (very rare).
Good Luck

Sounds like your sending unit sensor - if it was your pump going out, your engine would be history by now. Rule of thumb, if your oil check light ever comes on, it's usually too late to remedy the problem. You have a major issue, but since you've obviousely drove it quite a bit since then and it still hasn't seized up, I'm guessing you're ok...for now. Since you took it to a shop and they said you're ok, I'm assuming they checked your level and visually checked for leaks and found nothing. Either, you've got somethijng partially blocking your pick-up tube for the pump which is in your oil pan, or a electrical issue with the sensor. I would start by having someone check the sensor out and go from there...good luck.