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

P25EF

Vacuum Pump Control Circuit B Range/Performance

The secondary vacuum pump does not produce the expected vacuum within the commanded run time. Leak in the pump line or worn pump diaphragm reduces output.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / EF

Possible causes

  • Worn diaphragm or vanes inside the pump high
  • Cracked vacuum hose or loose connection medium
  • Sensor element aged beyond calibration window low

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–600 €
  • Estimated time: 0.5–2.5 h
  • Component: vacuum pump b
  • Component: vacuum lines
  • Component: vacuum sensor
  • 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