OBD2 code P0044: HO2S Heater Control Circuit High (Bank 1 Sensor 3)
The heated oxygen sensor on bank 1 is the third sensor further downstream, which exists only on systems with two catalyst stages.
Detected Root Component
Powertrain Component
Observed Symptoms
- Check engin light on
- Usually no noticeable drivability problem
- Catalyst monitor does not complete
- Emissions test or readiness check failed
Possible Causes
- Heater control wire shorted to battery voltage, e.g. chafed harness
- Heating element shorted internally
- Water in the connector causing leakage between pins
- Output driver or software of the engin control module
Tools Required
Interactive Diagnostic
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Parts likely to be the cause (Moteur (général))
Moteur (général)
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Frequently asked questions about code P0044
What does code P0044 mean? ▾
OBD2 code P0044: HO2S Heater Control Circuit High (Bank 1 Sensor 3). The heated oxygen sensor on bank 1 is the third sensor further downstream, which exists only on systems with two catalyst stages.
What are the symptoms of code P0044? ▾
Code P0044 may cause: Check engine light on, Usually no noticeable drivability problem, Catalyst monitor does not complete, Emissions test or readiness check failed. The intensity of these symptoms varies depending on the vehicle and driving conditions.
What causes code P0044? ▾
The most common causes of code P0044 are: Heater control wire shorted to battery voltage, e.g. chafed harness, Heating element shorted internally, Water in the connector causing leakage between pins, Output driver or software of the engine control module. A proper OBD2 diagnostic will pinpoint the exact cause.
Is it serious to drive with code P0044? ▾
Code P0044 has moderate severity (Warning). Short-term driving remains possible, but a prompt check is recommended to prevent worsening.
How do I fix code P0044? ▾
Start by reading the code with an OBD2 scanner, then follow the interactive decision tree on this page. Priority causes to check: Heater control wire shorted to battery voltage, e.g. chafed harness, Heating element shorted internally, Water in the connector causing leakage between pins, Output driver or software of the engine control module. Difficulty: Medium · Estimated time: 30-60min.