What does P0031 Generic: Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1) Nissan: Heated oxygen sensor (HO2S) 1 Bank 1 - heater voltage low mean?
P0031 is a diagnostic trouble code that indicates a low voltage signal in the oxygen (A/F) sensor heater control circuit for Bank 1 Sensor 1.
This code is applicable to OBD-II equipped vehicles, such as Toyota, VW, Ford, Dodge, Honda, Chevrolet, Hyundai, Audi, and Nissan.
The purpose of the oxygen sensor is to detect the amount of oxygen in the exhaust gas compared to the outside air.
The vehicle's computer then adjusts the air/fuel ratio going into the engine based on this information.
The oxygen sensor is equipped with a heater that is activated when the exhaust gas temperature is low to ensure accurate readings.
The P0031 code means that the resistance of the heater circuit is lower than normal, typically falling below.
8 A.
This code is similar to P0032, P0051, and P0052.
P0031 Symptoms
- MIL (malfunction indicator lamp) will illuminate
Possible P0031 Causes
- Short or open in the heater circuit in the sensor
- Failed O2 sensor heater
- Wiring/connectors broken/frayed leading to sensor and/or relay
- Failed PCM/ECM
Troubleshooting P0031 error code
- Inspect wiring and connectors leading to the sensor
- Check heater relay and fuse
- Use a digital volt ohm meter to check for 12 volts at the heater circuit feed, check the ground circuit for continuity, measure the resistance of the heater circuit and measure the resistance and voltage of the wiring
- Replace the air/fuel (O2 oxygen) sensor #1 on bank 1
