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

P2D10

Engine Pre-Ignition Above Threshold - Forced Limited Power

Pre-ignition events exceed a critical threshold. The ECM forces limited engine power to protect pistons, rings, and connecting rods from further damage.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberD / 10

Possible causes

  • Low-octane fuel under sustained high load high
  • Carbon deposits glow as hot spots medium

Inspection / repair

  • Difficulty: hard
  • DIY: shop recommended
  • Estimated cost: 200–3000 €
  • Estimated time: 1–12 h
  • Component: spark plugs
  • Component: fuel system
  • Component: ecm
  • MIL / check engine light
  • emissions-relevant
  • limp mode possible

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