DTC P0031-00: HO2S Heater Control Circuit Low (Bank 1/Sensor 1): General Description
WARNING: This page is about a different car, the 2021 Kia Soul. However, it is still accessible from the selected car via links, so may be relevant.
The normal operating temperature of the Heated Oxygen Sensor (HO2S) ranges from 350 to 850°C (662 to 1562°F). The Heated Oxygen Sensor (HO2S) heater greatly decreases the amount of time required for fuel control to become active. The PCM provides a pulse width modulated control signal to adjust current through the heater. When the Heated Oxygen Sensor (HO2S) is cold, the value of the resistance is low and the current in the circuit is high. On the contrary, if the temperature in the resistor of the Heated Oxygen Sensor (HO2S) rises, the current drops gradually.