Replace The Key Fob Battery on a Toyota 86, FRS or BRZ
Quick how-to guide on replacing the battery in your 2013-2015 Scion FRS (Toyota 86), Subaru BRZ, and even a Toyota Camary and Corolla using the same key fobs.
This guide does not cover reprogramming keys. If you're replacing a lost key, it'll need to be reprogramed to open the doors and start your car.
Remove and Replace Remote Entry Key Fob Battery
If you have a key ring attached to the fob, remove it.
Use a small screwdriver to gently pry the two halves of the key apart.
There is a small indentation you can use to get between the 2 halves at the top of the fob.
Remove the back cover.
Remove the transmitter module.
Open the transmitter module using your screwdriver, a key, or a coin.
It has a slot designed for this on the side.
Remove the rear cover for the transmitter module.
Remove the battery from the module.
It may require prying out with your small screw driver, just be gentle to make sure you don't break any of the retaining tabs.
Insert a new battery.
Install the module's back cover.
Place the module back into the key fog.
Make sure all the buttons, and the rubber membrane are in the correct alignment before placing the module in.
Replace the key fob's rear cover.
It should just snap shut.