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

P0252

Injection Pump Fuel Metering Control A Range/Performance (Cam/Rotor/Injector)

Injection pump metering control A does not respond as expected. A flow-deviating injector throws off cylinder balance — adjacent cylinders run leaner/richer to compensate, often masking the root cause until the trim limit is hit.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number2 / 52

Possible causes

  • Actuator drifted high
  • Sensor element aged beyond calibration window low
  • Sensor mounting loose - signal damping low

Inspection / repair

  • Difficulty: hard
  • DIY: shop recommended
  • Estimated cost: 300–2500 €
  • Estimated time: 2–10 h
  • Component: injection pump
  • Component: metering actuator a
  • MIL / check engine light
  • emissions-relevant
  • drive cycle required
  • 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