The tailgate is unlocked and locked at the same time as the rest of the vehicle: by unlocking and locking the driver's door with the key, remote control or central locking control button, and with the latch lever on the driver's door.
To open the tailgate, press the latch (see picture), and then lift the door. To close the rear door, pull it down on the inside handle, and then press down on the bottom of the door.
When the vehicle is moving, the rear door must be closed. This will avoid damage to it and the penetration of exhaust gases into the passenger compartment.
Unlocking the tailgate
If the rear door cannot be unlocked using the central locking control, it can be unlocked manually.
Attach a piece of cloth to the cover that is on the inside of the tailgate and open it with a small flathead screwdriver.
Push the release lever to the right and down as shown.
If you had to open the back door manually, then the back door is faulty. Contact your dealer's service center for repairs.