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

P025B Fuel Pump Module A Control Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

On demand-controlled fuel systems the engine module does not drive the pump itself but sends a pump control module the desired pump output on a separate control line, usually as a duty cycle; the module reports back on a monitor line or via CAN. P025B means pump module A receives a signal, but an invalid command – the duty cycle is outside the valid window or implausible. Ford's module signals this with a 20 % (±4 %) duty cycle on its monitor line; the check runs continuously at 11–16 V over 2–5 s. Whether the warning light comes on depends on the vehicle. Typical causes are contact resistance in the control line or connector that distorts the duty cycle, a poor ground or a faulty module.

Likely causes

Contact resistance or corrosion in the control line or connector distorting the duty cycle
Pump control module faulty
Interference or poor ground between engine module and pump module
Engine module software or output

Symptoms

  • Check engine light (manufacturer-dependent)
  • Hard or no start
  • Rough idle, surging
  • Lack of power from wrong fuel pressure

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time1–3 h

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

Parts involved

fuel pump control module afuel pump control wiringengine control module

Related codes

P025AP025CP025DP027BP064AP0627

References: law.cornell.edu, fordservicecontent.com, newtonnet.co.uk, roushcleantech.com.