After a few years of daily use, the battery in the key fob remote control of a 10th generation (2009, 2010, 2011 & 2012) Toyota Corolla can become weakened or simply stop working.
If you'd like to replace the key fob battery, check out my quick guide to the procedure at the link below.
Here's the DIY -
http://www.paulstravelpictures.com/2009-2012-Toyota-Corolla-Key-Fob-Battery-Replacement-Guide/index.htmlThe steps should be the same for other Toyota vehicles with similar combination car key / remote control units such as the Camry, RAV4, Yaris, Avalon, Venza, and 4Runner.
I hope someone finds it to be useful.
Cheers,
Paul