Press The Transmitter Unlock Switch Twice
WARNING: This page is about a different car, the 2006 Mitsubishi Montero. However, it is still accessible from the selected car via links, so may be relevant.
When the transmitter unlock switch is pressed twice, the ETACS-ECU energizes its door unlock relay to operate the driver's door lock actuator and the other door lock actuators for 0.5 second each in succession. Then, the doors will be unlocked.