This has been covered before, use the "search" function to find out if your vehicle is under the affected units. The problem is more than likely one of the oil pressure senders failing. Very easy to diagnose which one as both must break earth/ground for the light to go out(that is once the sufficient oil pressure is reached). Since both senders have only one connection/terminal all you need is a multimeter with "continuity buzzer" to check which one doesn't work as required. The resistor (it's pricey) is mounted on the driver side behind the panel next to throttle pedal. To change either sender you'll need 27 mm deep socket and some wobbly extensions to reach the one above starter motor. Apparently advice is to change both senders and resistor if your vehicle falls in to affected chassis number range. You aren't going to like the cost $$$$$ so better yet fit an oil gauge instead of the patsy light. I had the same problem some months ago, while diagnosing it was relatively easy, changing the senders was a bit challenging particularly the one above starter motor (high pressure unit) while the low pressure unit ( under the turbo) was a breeze. Beware that the senders are not the same despite looking identical one has the green band/circle on the body (RHS) and one none (LHS)
G'day mate I popped onto my Nissan dealer the other week and Explained the problem to them to which the told me it would be covered under extended warranty?
