O2 Sensor Negative Current Control Circuit High (Bank 1 Sensor 1)
The Vs negative line on bank 1, sensor 1 reads above the upper threshold. Often a short to positive or a damaged ECU sensor amplifier.
Affected components
- Oxygen sensor upstream
- Oxygen sensor wiring
Common causes
- High likelihood: Vs negative line shorted to positive
- Medium likelihood: Internal short in sensor
- 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.