Using Scan Tool
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2003 Lexus SC 430, 2003 Lexus RX 300, 2003 Lexus LX 470, 2003 Lexus LS 430, and 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
Start and warm engine up to normal operating temperature. Shut engine off. Connect scan tool to DLC3. See Figure. Start engine. Following scan tool manufacturer's instructions, check ignition timing.