p0031
Moderate
Subaru · SUVs & Crossovers
HO2S Heater Control Circuit Low (Bank 1 Sensor 1)
Quick Answer
Error code P0031 on your Subaru SUVs & Crossovers means: HO2S Heater Control Circuit Low (Bank 1 Sensor 1). This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Connect OBD-II scanner and verify code
2
Locate bank 1 sensor 1 oxygen sensor
3
Check sensor heater wiring for corrosion
4
Test heater resistance with multimeter
5
Verify ground connection and fuse condition
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
OBD-II scanner
Oxygen sensor
Wire connectors
Electrical grease
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