OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

P2244

O2 Sensor Reference Voltage Circuit Range/Performance (Bank 1 Sensor 1)

The reference voltage that the ECU supplies to the wide-band oxygen sensor on bank 1, sensor 1 drifts outside the expected range. The reference is the baseline against which the cell voltages are measured; a drift falsifies every lambda calculation.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number2 / 44

Possible causes

  • Reference circuit drift in ECU high
  • High resistance in reference wiring medium
  • Sensor element aged beyond calibration window low

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 upstream
  • Component: oxygen sensor wiring
  • Component: ecm
  • MIL / check engine light
  • emissions-relevant
  • drive cycle required

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication