P2248
O2 Sensor Reference Voltage Circuit Range/Performance (Bank 2 Sensor 1)
Bank 2 counterpart to P2244. The reference voltage at the wide-band oxygen sensor on bank 2, sensor 1 is outside its expected range and falsifies the lambda calculation.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Common causes
Ordered by how often each turns out to be the cause.
- Reference circuit drift in ECUCommon
- High resistance in reference wiringPossible
- Sensor element aged beyond calibration windowLess likely
Parts involved
- Oxygen Sensor Upstream B2
- Oxygen Sensor Wiring
- ECM
P2248 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.