GS300 & Is300
Disconnect Throttle Position (TP) sensor connector. Do not confuse TP sensor with accelerator pedal position sensor. Both sensors have 4-pin connectors and are mounted on throttle body See Fig 1. Measure resistance between terminals E2 and VC at TP sensor. Resistance should be 1200-3200 ohms at 68°F (20°C). If resistance is not 1200-3200 ohms, replace TP sensor.