Powertrain, generic · Fuel and air metering (injector circuit)

P025F Turbocharger/Supercharger Boost Sensor B Intermittent/Erratic

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Boost sensor B is a second boost pressure sensor, for a second turbo or bank on twin-turbo engines or a second stage. P025F counts brief excursions of its signal outside the valid range that are too short for the low or high code – the counterpart of P025E, which Ford sets after 10 such events in one drive cycle. No manufacturer using sensor B codes was found; the description follows CARB's input monitoring requirement and Ford's sensor A check.

Likely causes

Loose contact or corrosion at the sensor B connector
Wire breaking from vibration or heat
Sensor B faulty

Symptoms

  • Check engine light on
  • Occasional loss of power
  • Boost limited

Repair estimate

DifficultyEasyDIY possible
Parts and labour€30–200
Time0.3–1.5 h

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

Parts involved

boost pressure sensor bsensor wiring

Related codes

P025EP0239P0240P0241P0242

References: law.cornell.edu, fordservicecontent.com, en.wikipedia.org.