Monitor Description
WARNING: This page is about a different car, the 2004 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
If there is a defect in the sensor or an open or short circuit, the voltage level will deviate outside the normal operating range. The ECM interprets this deviation as a defect in the MAF sensor and sets a DTC.
Example:
When the sensor voltage output is less than 0.2 V or more than 4.9 V and if either the condition continues for more than 3 seconds.