O2 Sensor Negative Current Control Circuit Low (Bank 1 Sensor 1)
The negative-current (Vs negative) line on the bank 1, sensor 1 wide-band oxygen sensor is below the lower threshold. This line is the return path for the Nernst cell; loss of the signal blocks the lambda calculation.
Affected components
- Oxygen sensor upstream
- Oxygen sensor wiring
Common causes
- High likelihood: Vs negative line shorted to ground
- Medium likelihood: Nernst cell return open inside 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.