Possible Causes
WARNING: This page is about a different car, the 2003 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
This DTC uses two-trip detection logic. DTC is set when ECM detects MAF meter output is greater than 2.91 volts with Throttle Position (TP) sensor VTA circuit signal voltage of 0.42-0.86 volt with engine coolant temperature greater than 158°F (70°C) for more than 10 seconds with engine speed of 1500 RPM or less, or MAF meter output is less than one volt with TP sensor VTA circuit signal voltage of 3 volts or more for at least 10 seconds with engine speed of 2100 RPM or more. Possible cause is defective MAF meter.