>> A << Battery Installation
WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Do not allow water or dust to enter the inside of the transmitter assembly when it is open. Also, do not touch the precision electronic device.
Install a new battery to the transmitter assembly with its (+) side facing towards the master key side.
Battery required for replacement: Coin type battery CR1620