Can not open all doors by keys and inside button,only trunk is working,i did check fuses,this happen when my battery went dead !

check your fuses

There is a relay in the rear fuse block for the trunk release. marked trunk relay #36. It is marked on the under side of the lid. If you knew how they worked you could open it by jumping pin 30 to pin 87 in fuse box. on the side of the relay is a diagram of what pins are what . This system uses an electronic control module called ( the BCM ) body control module .When you push the inside release button , that sends a signal to the BCM ,then the BCM activates the relay opening the trunk . Well that won't help ,you won't believe where the fuse box is ! Fuse Block - Rear
In the rear compartment, behind the left wheel well. You could jump the wire at the BCM that goes to the relay. Can't you pull down one of the rear seats to gain access ?

You can always open the trunk and have someone small enough crawl through the trunk... as long as they are old enough to know how to unlock the door once inside (just pull on the door handle).

The key should work in the driver's door though... not sure why it won't.

can you manually unlock the lock and open the door?? Is it more than one door or just one specific door? If its just one door, yourcactuator inside the door may be bad or you have a wire issue. If its all the doors, more than likely you blew a fuse or a relay(id say fuse)

Assuming the car battery is ok (if not, buy a male to male cigarette lighter at the auto store and connect to another car until charged enough to unlock the doors...but don't try to crank the ignition!). The trunks won't open if the battery went dead with the alarm set because arming the alarm physically locks the releases.

Sounds like the key code is switched off because you replaced the key fob battery. Try unlocking the car manual with the key in the door lock. Then switch the ignition on to reactive the keyless entry. If this does not work, you might also try pressing the fob unlock button with the key in the door lock until the dash led flashes.

use your ignition key to open the trunk, the key hole is hidden just under the opening button and to the right side

Yes, insure that you have power to the trunk lock inside trunk, If not could be lose/broken wire or shot fuse. I am sure the key fob does work for the doors? If not have key fob battery replaced. Also, a quick check on power to trunk lock, check to see if have remote power button inside car, if it works power is good. Defective key fob would then be indicated.

if the doors and trunk are vacuumed operated, make sure all the doors are unlocked..this might make it easier to open the trunk..or get the car running and then try to open the trunk with the car running..turn key all the way to the left and push slowly in..I think it is vacuum operated like the mercedes

you can charge the battery from the engine compartment. check your owners manual that is the correct place to jump and to charge the battery.

you should have trunk key all cars trunk can be open remote by the inside. if any fails you always have a trunk key. check your ignition key .i seen ignition keys do both. it cranks car and open doors and trunk.