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

P2525

Vacuum Reservoir Pressure Sensor Circuit

General electrical fault on the vacuum reservoir pressure sensor circuit. The reservoir stores manifold or pump-generated vacuum for systems like brake booster, EGR actuators or HVAC dampers. Without a valid reading the ECM disables vacuum-pump duty cycle control.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / 25

Possible causes

  • Open or shorted wiring to the sensor high
  • Failed sensor element medium

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–400 €
  • Estimated time: 0.4–1.5 h
  • Component: vacuum reservoir pressure sensor
  • Component: sensor wiring
  • 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