Powertrain
Definition only
Lights the check engine lamp
P2238: O2 Sensor Pumping Current Circuit Low (Bank 1 Sensor 1)
Standardized SAE J2012 code · P22xx — Fuel & air metering and auxiliary emission controls
What does P2238 mean?
Pumping current at the bank 1 sensor 1 wide-band lambda probe is below the lower limit — short to ground or sensor at end of life.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Common causes
- High Pump line shorted to ground
- Medium Wide-band sensor aged
- Low Connector pins corroded - high contact resistance
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P2238 on the same make and model first.
P2238 in the community
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