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

P027C Fuel Pump Module B Control Circuit Low

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. Module B is a second pump module, for example on dual-tank commercial vehicles. P027C means the control circuit to pump module B reads low, typically a short to ground – the counterpart of P025C. Ford lists it in the low-pressure lift pump monitor of its 2023 diesels, monitored continuously and set within 0.5 s, without stating its own threshold or which vehicle has a module B.

Likely causes

Control line to module B shorted to ground
Connector at module B corroded or wet
Pump control module B faulty
Ground point

Symptoms

  • Check engine light on
  • Starting problems or stalling
  • Loss of power from low supply pressure

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–700
Time1–3 h

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

Parts involved

fuel pump control module bfuel pump control wiringengine control module

Related codes

P025CP027DP027AP027BP2633

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