P0627
Fuel Pump A Control Circuit/Open
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OBD2 code P0627 — Fuel Pump A Control Circuit/Open — indicates that the powertrain control module (PCM) has detected an unexpected open circuit condition in the control circuit responsible for operating the primary fuel pump. This means the PCM either cannot send a proper command signal to the fuel pump or is not receiving the expected feedback confirming the pump is operating. Because the fuel pump is essential for delivering pressurized gasoline or diesel to the engine's injectors, this fault can render the vehicle unable to start or cause it to stall unexpectedly while driving, which creates a significant safety concern.
The most common causes of P0627 include a faulty Fuel Pump Control Module (FPCM), damaged or corroded wiring in the fuel pump control harness, a failed fuel pump itself, a blown fuse, or a defective fuel pump relay. Ford and General Motors vehicles are particularly known for FPCM failures, and the module is often located in the engine bay or near the fuel tank where it is exposed to heat and moisture. Diagnosis should begin with a visual inspection of the relevant fuses and relay, followed by a wiring continuity check, before replacing more expensive components like the pump or control module.
Because this code can leave you stranded without warning, it should be addressed immediately. DIY repairs are feasible for mechanically inclined owners — checking fuses and relays is straightforward and low-cost — but diagnosing an open circuit in the wiring harness or confirming an FPCM failure may require a scan tool with live data capability and a digital multimeter. If you are not comfortable with electrical diagnostics, a qualified technician can pinpoint the fault efficiently and prevent unnecessary parts replacement.
Severity
Symptoms
- •Engine cranks but fails to start
- •Engine stalls while driving and cannot be restarted
- •No fuel pressure at the fuel rail when tested
- •Fuel pump not priming when ignition is switched to ON position
- •Check Engine Light illuminated
- •Loss of power or engine hesitation before stalling
Likely Causes
The fuel pump control module regulates voltage and current to the fuel pump. A failed or failing FPCM is a leading cause of P0627, particularly on Ford and GM vehicles where this module is a separate, known wear item.
Damaged, corroded, or broken wiring between the PCM/ECM and the fuel pump or FPCM can interrupt the control signal, triggering an open circuit fault code.
An internally failed fuel pump that draws excessive current or has an open internal winding can cause the control circuit to report an open condition to the PCM.
A faulty powertrain control module may fail to send or detect the control signal for the fuel pump circuit, though this is less common and should be diagnosed after ruling out external causes.
A blown fuse or a stuck-open fuel pump relay can prevent current from reaching the pump control circuit, resulting in an open circuit condition detectable by the PCM.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Inspect and replace blown fuses in the fuel pump circuit
- Test and replace the fuel pump relay
- Inspect wiring harness and connectors for corrosion, breaks, or shorts and repair as needed
- Replace the Fuel Pump Control Module (FPCM) if faulty
- Replace the fuel pump assembly if internal failure is confirmed