hi ,

well i have nissan vtc too 2004 and have the same problem , the sub tank doesnt work at all just driving with the primary tank , all nissans have same problems even the tank meter that tells u how much fuel left is not right , it happened to me when i was coming fro ksa to qatar had 1/4 tank and there was no fuel, didnt bother do fix it but if u want to fix it go to industrial area at any garage and just ask or go to the garage i go to - alkhaji garage الخرجي - street 16 - i have my patrol there now to change its colour from white to light blue :D , but i think it will cost u some money , plus 2004 always have alot of problems :( .

need anything about cars just talk to me and il reply mate ty .