GS300 & Is300

Start and warm engine up to normal operating temperature. Shut engine off. Connect scan tool to DLC3. See Figure. Use scan tool to read engine RPM. Using a timing light that can detect primary ignition signal, connect inductive lead to appropriate wire at ignitor. See Fig 1. Ignitor is located on top of driver's side strut tower.
Apply parking brake. Place transmission in Neutral. Start engine and maintain engine at 2500 RPM for 90 seconds and allow engine to idle. Ensure idle speed is 650-750 RPM. Install Jumper Wire (SST 09843-18020) between terminals TC and E1 on DLC1 located near driver's side strut tower. See Fig 2.
Timing marks are located on timing belt cover, near crankshaft pulley. Ensure base timing is 8-12 degrees BTDC at idle with transmission in Neutral, and with A/C and all accessories off. Remove jumper wire from DLC1. Ensure ECM controlled timing is 6-16 degrees BTDC. Shut engine off. Remove timing light and scan tool.

Fig 1: Connecting Timing Light At Ignitor (GS300 & IS300)

Fig 2: Installing Jumper Wire Between DLC1 Terminals (GS300 Shown; GS430 & IS300 Are Similar)