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

P252B

Engine Oil Quality Sensor Circuit Range/Performance

The oil quality sensor is electrically intact, but the readings do not match the model — for example permittivity that does not change after an oil change, or shifts inconsistent with km/h driven. Often a contaminated electrode or oil that does not fit the sensor calibration.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / 2B

Possible causes

  • Contaminated sensor electrode high
  • Oil grade outside the sensor calibration range medium
  • Sensor element aged beyond calibration window low

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 120–600 €
  • Estimated time: 0.5–2 h
  • Component: oil quality sensor
  • Component: engine oil

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