Diagnostic Aids
WARNING: This page is about a different car, the 2002 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.
After confirming DTC P0120, use scan tool to access CURRENT DATA to confirm throttle valve opening percentage with throttle open and closed. If percentage displayed on scan tool is always zero percent, VC circuit may be open, or VTA circuit may be open or shorted. If percentage displayed on scan tool is always 8-20 percent, VTA2 circuit may be open or shorted. If percentage displayed on scan tool is always 100 percent, E2 circuit may be open. Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.