What it means
HO2S Heater Control Circuit High (Bank 2 Sensor 2): the control-circuit voltage is above the expected range. The heater brings the oxygen sensor to operating temperature for closed-loop fuel control.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Bank 2 Sensor 2 is the heated oxygen sensor downstream of the catalytic converter on Bank 2. The control module monitors the heater control circuit and sets P0058 when its voltage is higher than expected, which may indicate a short to voltage or another heater-circuit fault.
Common causes
Most likely first.
- Heater control circuit shorted to voltage
- Heater element or wiring fault
Symptoms
- Check-engine light on
- Oxygen-sensor heater may warm slowly
- Fuel economy may decrease
- Emissions may increase
How to diagnose it
- Save freeze-frame data and check for related heater or voltage codes that could point to a shared circuit problem.
- Inspect Bank 2 Sensor 2 wiring and connector for damaged insulation, corrosion, loose terminals, or contact with a power wire or hot exhaust.
- Follow the wiring diagram to test the heater control wire for a short to voltage and inspect the heater element for an electrical fault.
- Check heater supply and control operation using the manufacturer's diagnostic procedure and the specified test conditions.
- If wiring and connections are intact, test the Bank 2 Sensor 2 heater against the manufacturer's specification before replacing the sensor.
Common fixes
- Repair wiring where the Bank 2 Sensor 2 heater control circuit is shorted to voltage.
- Repair loose, corroded, or heat-damaged connector terminals.
- Replace Bank 2 Sensor 2 if its heater element fails the specified test.
- Repair a confirmed fault in the heater supply or control circuit.
Can I keep driving?
If the engine runs normally, driving is generally possible, but emissions may rise while the sensor warms slowly. Arrange diagnosis soon because a short to voltage can affect the heater circuit.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.