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

P24F7

Exhaust Aftertreatment Fuel Air Purge Valve Stuck Closed

The aftertreatment HC dosing or reductant purge valve is stuck closed. The ECM commands purge but the line is not cleared, leaving residual fluid that can foul nozzles or freeze in cold weather. Subsequent dosing events also fail because backpressure does not match the model.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number4 / F7

Possible causes

  • Stuck closed by deposits or seized armature high
  • Open coil — valve never opens medium
  • Carbon or debris buildup preventing free movement low

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 200–900 €
  • Estimated time: 0.6–2.5 h
  • Component: aftertreatment purge valve
  • Component: dosing line
  • MIL / check engine light
  • emissions-relevant

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