Diagnostic Aids
WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.
Read freeze frame data using hand-held tester or OBD-II scan tool because freeze frame records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, or the air-fuel ratio was lean or rich at the time of the malfunction.
NOTE:
After confirming DTC P2120, P2122, P2123, P2125, P2127, P2128 and P2138 use the OBD-II scan tool or the hand-held tester to confirm the throttle valve opening percentage. See Fig 1.