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

P25F2

Turbocharger/Supercharger Boost Sensor C Circuit

A third boost pressure sensor (C) used on twin-stage or sequential boost systems returns no usable signal. Without it, boost control of the third stage runs open-loop or is disabled.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / F2

Possible causes

  • Open sensor element or broken signal wire high
  • Corroded connector at sensor pigtail medium

Symptoms

  • Check engine light on
  • Significant power loss / limp mode
  • Possible blue or black smoke from exhaust
  • Whistling or hissing sound from intake

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–400 €
  • Estimated time: 0.5–2 h
  • Component: boost pressure sensor c
  • 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