OBD2 code P0030: HO2S Heater Control Circuit (Bank 1 Sensor 1)
The upstream oxygen sensor on bank 1 (sensor 1, before the catalytic converter) only delivers a usable signal once its ceramic element is hot.
Detected Root Component
Powertrain Component
Observed Symptoms
- Check engine light on
- Usually no noticeable drivability problem
- Closed-loop control starts late after a cold start
- Emissions test or readiness check failed
Possible Causes
- Heater circuit interrupted, e.g. broken or chafed wire near the exhaust
- Heating element inside the sensor burnt out
- Connector corroded or terminal pushed back
- Heater supply fuse or relay faulty
- Output driver in the engine control module faulty
Tools Required
Interactive Diagnostic
Answer each question to calculate your diagnostic score.
No steps available.
Diagnostic Result
Score threshold guide
Was this diagnostic helpful?
Parts likely to be the cause (Moteur (général))
Moteur (général)
Photo d'illustration : Moteur (général)
© DTC-Logic.com
Click on an image to enlarge
Frequently asked questions about code P0030
What does code P0030 mean? ▾
OBD2 code P0030: HO2S Heater Control Circuit (Bank 1 Sensor 1). The upstream oxygen sensor on bank 1 (sensor 1, before the catalytic converter) only delivers a usable signal once its ceramic element is hot.
What are the symptoms of code P0030? ▾
Code P0030 may cause: Check engine light on, Usually no noticeable drivability problem, Closed-loop control starts late after a cold start, Emissions test or readiness check failed. The intensity of these symptoms varies depending on the vehicle and driving conditions.
What causes code P0030? ▾
The most common causes of code P0030 are: Heater circuit interrupted, e.g. broken or chafed wire near the exhaust, Heating element inside the sensor burnt out, Connector corroded or terminal pushed back, Heater supply fuse or relay faulty. A proper OBD2 diagnostic will pinpoint the exact cause.
Is it serious to drive with code P0030? ▾
Code P0030 has moderate severity (Warning). Short-term driving remains possible, but a prompt check is recommended to prevent worsening.
How do I fix code P0030? ▾
Start by reading the code with an OBD2 scanner, then follow the interactive decision tree on this page. Priority causes to check: Heater circuit interrupted, e.g. broken or chafed wire near the exhaust, Heating element inside the sensor burnt out, Connector corroded or terminal pushed back, Heater supply fuse or relay faulty. Difficulty: Medium · Estimated time: 30-60min.