OBD-II code family
Oxygen Sensor Heater Circuit Faults (24 codes)
24 related fault descriptions. Use each full code and the exact vehicle service information to identify its circuit, monitored condition, and required tests.
Codes in this family
This is the complete published member list for this guide. Each code retains its own page; shared diagnostic context does not mean that every member has the same test or repair.
- P0030HO2S Heater Control Circuit (Bank 1, Sensor 1)
- P0031HO2S Heater Control Circuit Low (Bank 1, Sensor 1)
- P0032HO2S Heater Control Circuit High (Bank 1, Sensor 1)
- P0036HO2S Heater Control Circuit (Bank 1, Sensor 2)
- P0037HO2S Heater Control Circuit Low (Bank 1, Sensor 2)
- P0038HO2S Heater Control Circuit High (Bank 1, Sensor 2)
- P0042HO2S Heater Control Circuit (Bank 1, Sensor 3)
- P0043HO2S Heater Control Circuit Low (Bank 1, Sensor 3)
- P0044HO2S Heater Control Circuit High (Bank 1, Sensor 3)
- P0050HO2S Heater Control Circuit (Bank 2, Sensor 1)
- P0051HO2S Heater Control Circuit Low (Bank 2, Sensor 1)
- P0052HO2S Heater Control Circuit High (Bank 2, Sensor 1)
- P0053HO2S Heater Resistance (Bank 1, Sensor 1)
- P0054HO2S Heater Resistance (Bank 1, Sensor 2)
- P0055HO2S Heater Resistance (Bank 1, Sensor 3)
- P0056HO2S Heater Control Circuit (Bank 2, Sensor 2)
- P0057HO2S Heater Control Circuit Low (Bank 2, Sensor 2)
- P0058HO2S Heater Control Circuit High (Bank 2, Sensor 2)
- P0059HO2S Heater Resistance (Bank 2, Sensor 1)
- P0060HO2S Heater Resistance (Bank 2, Sensor 2)
- P0061HO2S Heater Resistance (Bank 2, Sensor 3)
- P0062HO2S Heater Control Circuit (Bank 2, Sensor 3)
- P0063HO2S Heater Control Circuit Low (Bank 2, Sensor 3)
- P0064HO2S Heater Control Circuit High (Bank 2, Sensor 3)
What these codes mean
These twenty-four codes compare oxygen-sensor heater control, low/high and heater-resistance conditions. The member list retains each bank, sensor number and detected condition. Heater monitoring is different from evaluating the oxygen signal or the catalyst’s conversion performance.
The historical grouping assigns bank1 sensor1 to P0030–P0032/P0053, sensor2 to P0036–P0038/P0054 and sensor3 to P0042–P0044/P0055. Bank2 sensor1 uses P0050–P0052/P0059, sensor2 uses P0056–P0058/P0060 and sensor3 uses P0062–P0064/P0061. Locate each sensor through the engine’s actual exhaust diagram. Sensor3 is not a universal second post-catalyst sensor or proof of a particular converter count.
Low/high, control/open and monitored resistance are different criteria. The controller may evaluate current, voltage, calculated resistance or driver status under specific conditions. A scan-tool value is not automatically the same measurement as a disconnected hand-meter test. Do not transfer a cold resistance band or a low/high polarity rule between sensors or engines.
Manufacturer examples also have boundaries. Ford’s covered heater summaries describe sensor-dependent monitors. The listed Volkswagen tables preserve open/low/high and sensor-number distinctions. Applicable Mitsubishi procedures distinguish their own current and voltage checks. A software or sensor replacement bulletin must match the exact vehicle and listed DTC; a nearby code in its summary is not an explicit replacement mapping.
Save the complete scan, identify the correct sensor and test the specified supply, return and control paths. Do not power an unknown heater directly, bridge signal pins or treat an unplug response as complete proof of a bad sensor. Work on cooled exhaust with the prescribed electrical isolation. Repair the confirmed serviceable fault and verify heater operation and the relevant monitor. A sensor replacement estimate prices only that diagnosed job, not every heater fault.
Identify the circuit on your vehicle
Match the full DTC, reporting module, and any failure-type suffix to the service information for your exact year, make, model, engine, and equipment. An identifier alone does not establish installed hardware count, location, connector pinout, or a universal measurement.
Where the manufacturer publishes its own meaning for this code, that is the one to work from — it describes the actual component on your vehicle, which the generic definition cannot. Keep the generic description for what it is good for: it tells you which subject area the standard assigned the code to, which is useful context when the two appear to disagree. If they do disagree, follow the manufacturer.