How do you program a 2009 Toyota matrix key?

To program a key for a 2009 Toyota Matrix, you typically need at least one working key. Insert the working key into the ignition and turn it to the "On" position for a few seconds, then back to "Off." Remove the key, insert the new key, and turn it to the "On" position within 15 seconds. If done correctly, the security light will blink, indicating the new key is now programmed. If you don't have a working key, you may need to visit a dealership or a locksmith with specialized equipment.