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

P25AE

Piston Cooling Oil Pressure Too Low

With the piston-cooling jets commanded on, the dedicated oil-pressure sensor in that gallery reads below the safe threshold. Insufficient flow to the jets means real piston cooling is not happening — the ECM warns the driver and may reduce torque to protect the pistons.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / AE

Possible causes

  • Low engine oil level high
  • Sludge-clogged oil gallery medium
  • Worn oil pump low

Inspection / repair

  • Difficulty: hard
  • DIY: shop recommended
  • Estimated cost: 200–2500 €
  • Estimated time: 1–8 h
  • Component: oil pump
  • Component: oil gallery
  • Component: piston cooling solenoid
  • 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