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

P253F

Engine Oil Deteriorated

The oil quality monitor concludes that the engine oil has reached the end of its useful life — based on permittivity, soot content, fuel dilution and total operating hours. The ECM requests an oil change before the next regen cycle to prevent accelerated bearing wear.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / 3F

Possible causes

  • Service interval exceeded high
  • High DPF regeneration load with fuel dilution medium

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • Estimated cost: 60–200 €
  • Estimated time: 0.3–1 h
  • Component: engine oil
  • MIL / check engine light

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