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 P0100, P0102 & P0103.
DTC P0101 will set when engine is warmed up, throttle valve is fully closed and mass air flow meter output is greater than 2.2 volts for more than 10 seconds with engine speed less than 1,000 RPM (2 trip detection logic). DTC will also set when engine is running, VTA is .64 volts or more and mass air flow meter output is less than .4 volts. Possible cause is a faulty mass air flow meter.