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

P0519

Idle Air Control System Performance

The idle air control system is electrically intact, but the actual idle airflow does not match the commanded value - typical for a sticky valve, intake leak, or carbon build-up around the throttle bore.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number5 / 19

Possible causes

  • IAC valve sticking due to carbon high
  • Intake leak disturbs idle metering medium

Symptoms

  • Check engine light on
  • Idle speed too high, too low, or unstable
  • Possible stalling at idle or after cold start

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • Estimated cost: 80–320 €
  • Estimated time: 0.5–1.8 h
  • Component: idle air control valve
  • Component: intake manifold
  • Component: throttle body
  • 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