P0031HO2S Heater Control Circuit Low (Bank 1 Sensor 1)
O2 sensor heater control circuit on bank 1, sensor 1 reports low voltage. Likely shorted to ground or open in the heater control wire. The heater warms the sensor element to operating temperature (~600 °C); without it the sensor stays inactive in closed loop and the ECM cannot trim mixture.
Can I keep driving? With caution
You can drive to the shop, but do not postpone the repair. The problem may worsen and damage other components.
Sistema Afectado
Aire / Combustible · Inyección, MAF, MAP, O₂
Relacionado con la mezcla aire-combustible: sensores de flujo, presión, inyectores o bomba.
Espacio para vendedores de repuestos
Aún no hay un anunciante en este espacio.
Possible Causes
The components or conditions that trigger this code
- 1Heater control wire shorted to ground Heater element internally shorted Connector pins corroded - high contact resistance
How to Fix It — Step by Step
Recommended diagnostic and repair procedure
- 1Difficulty: easy. Estimated time: 0.5-1.5 hours. Estimated cost: €80-€
- 2DIY possible
Note: This information is for general reference. For precise diagnostics and safety repairs, always consult a certified mechanic.
Estimated Cost
Approximate range in USD (varies by region and shop)
Varies by diagnosis
* Diagnosis only: $50–$150
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