Open circuit, corroded or loose terminals in the fuel pump control wiring or connectors; Faulty fuel pump relay or its socket (where fitted); Blown fuel pump fuse caused by a failing pump drawing excess current; Failed fuel pump or an open internal winding in the pump; Faulty fuel pump driver or control module (on systems with a separate module); Poor earth connection on the pump circuit or module; Internal fault in the engine control unit output driver.

P0627

Fuel Pump A Control Circuit/Open.

Generic
Powertrain
Generic code
High severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
6: AreaComputer and output circuits
27: FaultThe specific fault in that area

What it means

P0627 means the engine control unit has detected an open circuit in the control circuit for fuel pump 'A'. The control unit monitors the output that commands the fuel pump, either directly or through a relay or separate pump driver module. If it sees a voltage or current state that indicates no continuity, it sets the code. Circuit layout varies by model and engine, so the exact component being monitored should be confirmed from the wiring diagram.

Symptoms

Engine cranks but will not start
Intermittent stalling or cutting out while driving
Loss of power or hesitation under load
Fuel pump not heard priming when the ignition is switched on
Engine management warning light on
Hard or long starting when hot or cold, depending on the fault

Possible causes

Open circuit, corroded or loose terminals in the fuel pump control wiring or connectorslikely
Faulty fuel pump relay or its socket (where fitted)likely
Blown fuel pump fuse caused by a failing pump drawing excess currentpossible
Failed fuel pump or an open internal winding in the pumppossible
Faulty fuel pump driver or control module (on systems with a separate module)possible
Poor earth connection on the pump circuit or modulepossible
Internal fault in the engine control unit output driverrare

How to diagnose

Read all stored codes and freeze frame data to see when the fault set and whether other fuel or communication codes are present
Check the fuel pump fuse and relay, and inspect the relay socket for heat damage or corrosion
Listen for the pump priming when the ignition is switched on, and use a scan tool's active test if the vehicle supports it
Inspect the wiring and connectors between the control unit, relay or driver module and the pump, looking for chafing, water ingress and pushed-back pins
Check supply voltage and earth at the pump connector with the circuit commanded on, following the model's wiring diagram
Test circuit continuity and resistance of the control wire with the battery disconnected and the connectors unplugged
Measure pump current draw or check the pump winding resistance against the manufacturer's specification
Check for relevant technical service bulletins for the specific model and engine, then check the driver module or control unit last

How to fix

Repair or replace damaged wiring and clean or replace corroded connector terminals
Replace a faulty fuel pump relay or damaged relay socket
Replace the fuel pump if it is open circuit or drawing excess current, and replace the fuse if it has blown
Restore poor earth connections to a clean, secure metal contact
Replace a faulty fuel pump driver module or control unit only after the wiring and pump have been proven good, and code or program it as the manufacturer requires

Can I keep driving?

High severity

Avoid driving if the car is stalling or struggling to start, as loss of fuel supply can cut the engine without warning and affect braking and steering assistance. Have it repaired promptly, and do not rely on the car for any journey until the fault is found.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.