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

P0492

Secondary Air Injection System Insufficient Flow (Bank 2)

AIR system flow on bank 2 is below threshold during the cold-start self-test — typically a clogged check valve, leaking hose, or weak air pump.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number4 / 92

Possible causes

  • Check valve clogged high

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 100–800 €
  • Estimated time: 0.7–3 h
  • Component: secondary air injection pump
  • Component: secondary air check valve
  • MIL / check engine light
  • emissions-relevant

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