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

P258A

Vacuum Pump Control Circuit A/Open

The control circuit driving the electric vacuum pump (used to maintain brake-booster vacuum on direct-injection or hybrid powertrains where the engine is not always running) is open. The ECM cannot run the pump on demand — booster vacuum drops, pedal feel hardens, brake assist may be reduced.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / 8A

Possible causes

  • Open control wire to the pump high
  • Failed driver in the control module medium

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 150–700 €
  • Estimated time: 0.5–2.5 h
  • Component: vacuum pump
  • Component: wiring harness
  • 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