P0057
HO2S Heater Control Circuit Low (Bank 2 Sensor 2)
HO2S Heater Control Circuit Low (Bank 2 Sensor 2): the control-circuit voltage is below the expected range. The heater brings the oxygen sensor to operating temperature for closed-loop fuel control.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
Common causes
Ordered by how often each turns out to be the cause.
- Heater wire shorted to groundCommon
- Connector pins corroded - high contact resistanceLess likely
- Harness chafing through insulationLess likely
Parts involved
- Oxygen Sensor Heater
- Sensor Wiring
P0057 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.