Powertrain
generic / SAE
P2251
O2 Sensor Negative Current Control Circuit (Bank 1 Sensor 1)
The negative current control line (Vs−) of the wide-band lambda sensor on bank 1 sensor 1 is open or out of range. Used as the virtual ground reference for the Nernst cell.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number2 / 51
Possible causes
- Vs− line open high
- Wide-band sensor failed medium
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 120–600 €
- Estimated time: 0.5–2 h
- Component: oxygen sensor wideband
- Component: oxygen sensor wiring
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012