O2 Sensor Reference Voltage Circuit High (Bank 1 Sensor 1)
The reference voltage on the bank 1, sensor 1 wide-band oxygen sensor reads above the upper threshold. Common with a short to a positive supply or a corroded connector with leakage current.
Affected components
- Oxygen sensor upstream
- Oxygen sensor wiring
Common causes
- High likelihood: Reference line shorted to positive
- Medium likelihood: Connector corroded with leakage
- Low likelihood: Supply wire pinched against B+ source
Possible symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.