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

P0447

Evaporative Emission System Vent Control Circuit Open

The ECU detected an open circuit on the EVAP vent valve control. The vent valve is needed to seal the system for leak diagnostics; with the circuit open the leak test cannot complete.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number4 / 47

Possible causes

  • Vent valve circuit open high
  • Wiring or connector fault medium
  • Pin pushed back out of connector body low

Symptoms

  • Check engine light on
  • Possible smell of fuel near tank or engine bay
  • Failed emissions inspection
  • Loose-cap warning may appear

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • Estimated cost: 40–300 €
  • Estimated time: 0.3–1.5 h
  • Component: evap vent valve
  • Component: vent valve wiring
  • 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