Nissan Repair Questions? Ask a Mechanic for Answers ASAP
Hello my name is ***** ***** thank you for your question
Try using the spare key and open the trunk and see id the alarm turns off
Let me know how you make out
To open the gas door have someone hold the release lever and try to use a small screw driver to see if the door will pop open. Once you get it open, use some WD30 on the hinge of the gas door.
The reason why the alarm would not turn off from the passenger door is cause the tamper switch most likely fell off that lock cylinder. On all the lock cylinders including the truck, there is a tamper switch which turns the alarm on and off through the lock cylinder. It's not uncommon to find one has fallen off. If the car was slim jimmed at one time it could have been knocked off. A link below shows how the tamper switch is laid out so you know what to look for if you decide to re-attach the passenger tamper switch.
If you have any more questions on this, please feel free to ask.
If not, and you're satisfied with my help, please Rate me. I hope I have provided you with Excellent Service.