Powertrain, generic (extended)

P25EF Vacuum Pump Control Circuit B Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P25EF says that the B circuit driving the electric vacuum pump is electrically present but its behaviour does not match the command: the feedback on the switched side looks implausible, or the pump runs without the expected effect on brake vacuum. No manufacturer documents P25EF publicly. Ford's hybrid OBD summary shows the type of logic used on the neighbouring circuit A, where P258B combines an out-of-window monitoring voltage with the relay off and a reading under 250 mV with the relay on. FCA's bulletin S1805000006 ties the A-circuit performance code to pumps that cannot hold enough vacuum and has hoses, check valves, fuses and terminals inspected first. A similar approach suits circuit B. CARB requires plausibility monitoring of such outputs. The brake pedal may feel firmer than usual.

Likely causes

Worn vacuum pump that runs but builds too little vacuum
Leaking vacuum hose or faulty check valve
Corroded terminals causing an unstable feedback voltage

Symptoms

  • Brake pedal firmer than normal
  • Vacuum pump running longer or more often
  • Warning lamp on

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–700
Time0.5–3 h

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

Parts involved

vacuum pumpvacuum linesvacuum sensor

Related codes

P25EEP25F0P25F1P258BP0556

References: fordservicecontent.com, static.nhtsa.gov, law.cornell.edu.