Diagnostic Aids
WARNING: This page is about a different car, the 2002 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.
After confirming DTC P0120, use Toyota hand-held tester or scan tool to access CURRENT DATA to confirm throttle valve opening percentage with throttle open and closed. If percentage displayed on hand-held tester or scan tool is always zero percent, VC circuit may be open, or VTA circuit may be open or shorted. If percentage displayed on hand-held tester or scan tool is always 100 percent, E2 circuit may be open. Using hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.