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

P24C1

EVAP System Leak Detection Pump Switching Valve Performance Stuck Off

Same as P24C0 with the valve stuck off. The evaporative system captures fuel vapor from the tank and purges it into intake; leaks or stuck purge valves leak hydrocarbons and cause emissions failures.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number4 / C1

Possible causes

  • Valve stuck off high
  • Carbon or debris buildup preventing free movement low
  • Component wear with age - mechanical play 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: medium
  • DIY: possible
  • Estimated cost: 120–400 €
  • Estimated time: 0.6–1.8 h
  • Component: evap leak detection pump switching 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