O2 Sensor Pumping Current Circuit (Bank 1 Sensor 1)
The pumping current line of the wide-band lambda sensor on bank 1 sensor 1 is unable to operate. Wide-band sensors regulate exhaust oxygen to a reference cell via this pumping current — without it, AFR cannot be measured.
Affected components
- Oxygen sensor wideband
- Oxygen sensor wiring
Common causes
- High likelihood: Pumping current line open
- Medium likelihood: Wide-band 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.