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P24D9

EVAP System Pressure Sensor or Switch B Circuit Intermittent

Same as P24D5 with intermittent or erratic signal. 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.

  • Check engine light: Yes
  • Emissions related: Yes
  • Repair difficulty: easy

Symptoms

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

Common causes

Ordered by how often each turns out to be the cause.

  • Intermittent contact at connectorCommon
  • Connector with intermittent contact under vibrationLess likely
  • Harness routed against vibrating componentLess likely

Parts involved

  • EVAP Pressure Sensor B

P24D9 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.