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

P252D

Engine Oil Quality Sensor Circuit High

Sensor signal voltage above the upper limit — typically a short to reference voltage or an open signal return.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / 2D

Possible causes

  • Signal wire shorted to reference voltage high
  • Connector pins corroded - high contact resistance low
  • Supply wire pinched against B+ source low

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 120–500 €
  • Estimated time: 0.5–2 h
  • Component: oil quality sensor
  • Component: sensor wiring

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