2009 Lexus LX 570 Owners Manual - Page 107

1-6. Theft deterrent system Engine immobilizer system The vehicle's keys have built-in transponder chips that prevent the engine from starting if the key has not been previously registered in the vehicle's on-board computer. Never leave the keys inside the vehicle when you leave the vehicle. The indicator light flashes after the "ENGINE START STOP" switch has been turned OFF to indicate that the system is operating. n System maintenance The vehicle has a maintenance-free type of engine immobilizer system. n Conditions that may cause the system to malfunction l If the key is in contact with a metallic object l If the key is in close proximity to or touching a key to the security system (key with a built-in transponder chip) of another vehicle 108