Circuit Description
WARNING: This page is about a different car, the 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
For circuit description, see Circuit Description under DTC P0120, P0122, P0123, P0220, P0222, P0223 OR P2135. DTC is set when difference between VTA and VTA2 is out of range for 10 seconds when idling, but for 2 seconds when idle is off. Possible cause is a faulty Throttle Position (TP) sensor.