How do you program a transponder key on a 2009 Mitsubishi Galant?

To program a transponder key for a 2009 Mitsubishi Galant, first, insert an unprogrammed key into the ignition and turn it to the "On" position without starting the engine. After about 10 seconds, turn the key back to the "Off" position and remove it. Repeat this process for a total of three times, then turn the key to the "On" position again. This should program the new key, allowing it to start the vehicle. If unsuccessful, you may need to consult a dealership or professional locksmith for assistance.