O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)
The ECU detects an abnormally high voltage from the upstream O2 sensor on bank 2. Indicates persistently rich exhaust, shorted sensor or wiring shorted to voltage.
Affected components
- Oxygen sensor b2s1
- Oxygen sensor wiring
- Fuel injector bank2
Common causes
- High likelihood: Bank 2 running rich (leaking injector, high fuel pressure)
- Medium likelihood: Signal wire shorted to voltage
- Medium likelihood: Upstream O2 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.