P0031
Low SeverityHO2S Heater Control Circuit Low (Bank 1, Sensor 1)
Emissions System
What Does P0031 Mean?
The O2 sensor heater circuit voltage is lower than expected on the upstream bank 1 sensor. Usually means an open circuit in the heater element.
Common Fix
Replace O2 sensor
Estimated Cost (DIY)
$30 - $100
Symptoms
- ⚠️Check engine light
- ⚠️Poor fuel economy when cold
- ⚠️Higher emissions
- ⚠️Slow O2 sensor response
Related Symptoms
Common Causes
How to Diagnose P0031
- 1Check fuse and relay for O2 heater
- 2Inspect connector for corrosion
- 3Measure heater element resistance
- 4Check for power and ground at sensor
OEM Diagnostic Flowchart
Scroll to load technician if/then branches.
Read live data and freeze frame for P0031 to pinpoint the cause before buying parts.
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Related Resources
Repair guides, symptom pages, and wiring diagrams related to P0031.
OEM Manual Evidence
Browse →A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Acadia FWD V6-3.6L Service Manual | Operation CHARM Operation CHARM : Car repair ma...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Acadia AWD V6-3.6L Service Manual | Operation CHARM Operation CHARM : Car repair ma...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Sierra 1500 2WD V8-4.8L Service Manual | Operation CHARM Operation CHARM : Car repa...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Sierra 1500 2WD V8-5.3L Service Manual | Operation CHARM Operation CHARM : Car repa...
Related Symptoms
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Exact Repair Workflows
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Open the exact repair flow most commonly associated with P0031 on this vehicle.
Open the exact repair flow most commonly associated with P0031 on this vehicle.
Open the exact repair flow most commonly associated with P0031 on this vehicle.
Related Codes
The oxygen sensor heater circuit on the upstream (pre-cat) sensor of bank 1 has a fault. The heater gets the O2 sensor to operating temperature quickly for proper fuel trim.
The heater in the upstream O2 sensor on bank 1 is not working properly. The heater brings the sensor to operating temperature quickly.
Frequently Asked Questions
- What does P0031 mean?
- P0031 means the upstream O2 sensor heater on bank 1 has low voltage — usually a burned-out heater inside the sensor.
- Is P0031 a cheap fix?
- Yes, O2 sensors cost $30-$100 DIY. It is one of the easier sensor replacements.
Related Repair Guides
If your vehicle has triggered P0031, these DIY repair guides may help: