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

P02CA

Turbocharger/Supercharger B Overboost Condition

Boost pressure on the secondary turbocharger/supercharger (B) on a sequential or twin-charged setup is above the upper threshold. Wastegate stuck closed, VGT vanes stuck, or boost pressure sensor reads high.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number2 / CA

Possible causes

  • Wastegate stuck closed high
  • VGT vanes stuck closed 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: hard
  • DIY: shop recommended
  • Estimated cost: 200–3000 €
  • Estimated time: 1.5–8 h
  • Component: turbocharger b
  • Component: wastegate b
  • Component: boost pressure sensor b
  • MIL / check engine light
  • emissions-relevant
  • limp mode possible

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