O2 Sensor Reference Voltage Circuit (Bank 1 Sensor 1)
The reference voltage line that powers the wide-band sensor cell on bank 1 sensor 1 is missing or out of tolerance. Without correct reference, the AFR calculation is invalid.
Affected components
- Oxygen sensor wideband
- Oxygen sensor wiring
Common causes
- High likelihood: Reference voltage line open
- Medium likelihood: Wide-band sensor failed
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.