Powertrain, generic (extended)

P24D9 EVAP System Pressure Sensor/Switch B Circuit Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P24D9 covers a sensor B signal that keeps flickering instead of failing outright. Mitsubishi's 2023 Outlander PHEV runs this check once per drive cycle inside the parked leak test, when the controller wakes at its scheduled times and coolant and intake air lie between 4 and 35 °C. It counts how often the tank pressure signal crosses the sensor's own filter value and stores the code after more than 20 crossings; the display then asks for a refuelling-system service. The service hints name the tank pressure sensor, the tank differential pressure sensor and their wiring. Shaking the harness while watching live data often reveals the spot. Steady low or high voltages fall under P24D7 or P24D8, implausible but stable readings under P24D6.

Likely causes

Loose terminal or poor contact at the tank pressure sensor
Harness chafed along the fuel tank
Tank pressure or tank differential pressure sensor unstable

Symptoms

  • Malfunction indicator lamp on
  • Refuelling system service message on the display

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–400
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

evap pressure sensor b

Related codes

P24D5P24D6P24D7P24D8P0454

References: mitsubishitechinfo.com, law.cornell.edu.