I have a 2005 volvo xc90 2.5t and it's alarm system is not working. The red light on the dashboard is not blinking and it doesn't sound any alarm, no matter what I do.There's no indicator about the alarm system needing repairing. Also the fuel tank door doesn't lock. I have to manually push the pin that locks the door. The opening button inside the car works fine. Anybody know whats wrong? I wouldn't want to take it to a repairshop since they charge so much around here.

 

Ok so I found out that the fuel tank door solenoid is working fine. So the problem must be somewhere deeper since the car doesn't send the electricity to the solenoid which would lock the door. But it sends it when I press the opening button so it cant be the wirings either.

 

Actually the fuel door lock itself 10 minutes after you lock the car.
strange but it is like this, setting can be change via vida