O2 Sensor Reference Voltage Circuit Low (Bank 2 Sensor 1)
Bank 2 counterpart to P2245. The reference voltage on bank 2, sensor 1 is below the lower threshold — typically a short to ground or failed ECU output.
Affected components
- Oxygen sensor upstream b2
- Oxygen sensor wiring
Common causes
- High likelihood: Reference line shorted to ground
- Low likelihood: ECU reference output failed
- Low likelihood: Connector pins corroded - high contact resistance
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.