The engine immobilizer is a state-of-the-art anti-theft system. When you insert your key into the ignition switch, the key transmits an electronic code to the vehicle. The engine will only start if the code in the transponder chip inside the key matches the code in the vehicle’s immobilizer. Because the transponder chip is embedded in the key, it can be costly to replace. If you lose a key, your Toyota dealer can help, or you can find a qualified independent locksmith to perform high security key services at www.aloa.org.