How to fix 2002 VW golf trunk lock?

1, trunk lock can not be locked any time
2, "door open" light on all time, tell me trunk is not close.
3, when you push the putton(trunk open) there is no machines runing sounds, but there is electric fail sound.
4, key fob can not lock car, only if turn on engine and open all door and close trunk first and any other doors.
the key fob can lock the car but there is no beep sound(tells you car is not properly locked).
5, if you open trunk after engine off , all door can not be locked by fob, by key only(7 times happen of 10 times).

Gary Xue
January 2012