Intake Air O2 Sensor Reference Voltage Circuit Low Bank 1
The reference voltage supplied to the intake air oxygen sensor on bank 1 reports a low condition. Lambda measurement on the intake side is unreliable.
Affected components
- Intake air o2 sensor b1
- Wiring harness
- Ecm
Common causes
- High likelihood: Reference wire shorted to ground
- Medium likelihood: Internal short in sensor reference
- 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.