Critical Safety risk Powertrain-code

P0031

P0031 - Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1)

Detailed information on troubleshooting and repairing a p0031 automotive trouble code which refers to an oxygen sensor heater circuit that is low. Also includes links to relevant forum topics on the code.

Pull over safely and book service immediately

This code is flagged as a safety risk and rated Critical. Avoid driving until a technician has inspected the vehicle.

Symptoms

A short or open in the heater circuit in the sensor
A failed O2 sensor heater
Wiring/connectors broken/frayed leading to sensor and/or relay
Failed PCM/ECM

Likely causes

A short or open in the heater circuit in the sensor
A failed O2 sensor heater
Wiring/connectors broken/frayed leading to sensor and/or relay
Failed PCM/ECM

Labor estimate

2h typical

Range: 1h – 4h

Parts cost

$0 – $500

Range varies by year/make/model

Information shown is reference-grade and may vary by vehicle. Always have a qualified technician confirm the cause before any repair.