Motor Vehicle Expert
OBD fuel pump control circuit guide

P0627 Code Meaning UK

P0627 means “Fuel Pump A Control Circuit Open”. In plain English, the ECU or PCM has detected an open circuit in the fuel pump control circuit. This can stop the fuel pump receiving the correct command, cause no-start, cutting out, low fuel pressure, poor acceleration, engine stalling or a vehicle that cranks but will not fire.

📅 Updated June 2026 🇬🇧 UK diagnostic guide 🛠 Fuel pump circuit advice
Quick answer Diagnosis steps Fault Codes Hub
✓ Fuel pump circuit fault explained ✓ Can you drive advice ✓ UK repair cost guide ✓ No-start checks included
Quick answer Meaning Symptoms Causes Severity Can you drive? Repair costs Diagnosis Vehicles affected Common mistakes MOT impact Used car advice Related guides FAQs
Quick answer

What does P0627 mean?

P0627 means the ECU has detected an open circuit in the fuel pump A control circuit. “Open circuit” usually means the electrical path is broken, disconnected, not completing properly or not giving the ECU the response it expects.

This fault can be serious because the fuel pump is responsible for delivering fuel pressure to the engine. If the pump is not powered or controlled correctly, the engine may crank but not start, stall while driving or lose power under load.

Do not replace the fuel pump blindly. The fault may be a fuel pump relay, blown fuse, damaged wiring, corroded connector, fuel pump control module, bad earth, ECU command issue or the pump itself.

Most important first check

Check fuel pump fuse, relay, pump command, voltage at the pump, ground and related no-start codes.

Main risk

The vehicle may not start, may cut out or may lose fuel pressure while driving.

Best next step

Test the fuel pump control circuit before replacing the pump.

Back to Fault Codes Hub Car Won’t Start Diagnosis
Fault code meaning

P0627 — Fuel Pump A Control Circuit Open

The fuel pump control circuit allows the ECU, fuel pump relay or fuel pump control module to power and control the fuel pump. On many vehicles, the ECU does not simply feed the pump directly. It may command a relay or module, then monitor whether the circuit responds correctly.

When P0627 appears, the ECU believes the fuel pump control circuit is open. That means the circuit may be broken, disconnected, missing a feed, missing a ground, suffering a failed relay, damaged wiring or a faulty control module.

Because this circuit affects fuel delivery, P0627 links closely with no-start and drivability faults such as car cranks but won’t start, car won’t start diagnosis, P0171 system too lean, P0201 injector circuit and P0300 random misfire.

Mechanic view

Why P0627 needs proper circuit testing

I would not fit a fuel pump just because P0627 is stored. I would first check whether the pump is being commanded, whether the relay is switching, whether voltage reaches the pump and whether the pump ground is good.

A fuel pump can be perfectly good but still not run if the relay, fuse, control module, wiring or earth path is faulty. Equally, a pump can fail internally and draw no current, which may also make the circuit look open.

The best diagnosis is electrical testing plus fuel pressure testing. Guessing parts can get expensive quickly.

Symptoms

Common symptoms of a P0627 code

P0627 symptoms are often related to fuel pressure, starting and cutting out. Some vehicles may still run intermittently if the circuit fault comes and goes.

Engine cranks but won’t start

The starter may turn the engine, but the engine will not fire if fuel pressure is missing.

Engine cuts out

The vehicle may stall if the fuel pump control circuit opens while driving.

No fuel pump prime

You may not hear the pump prime briefly when the ignition is switched on.

Poor acceleration

Low or unstable fuel pressure can cause hesitation and weak acceleration.

Limp mode

The ECU may reduce power if fuel delivery cannot be trusted.

Engine management light

The engine warning light may appear with P0627 and related fuel-pressure codes.

Hard starting

The engine may take longer to start if fuel pressure builds slowly or intermittently.

Lean running symptoms

Low fuel pressure may cause lean codes, misfires or rough running.

Intermittent no-start

A loose connector or relay fault may make the car start sometimes and fail other times.

Common causes

What causes P0627?

The most likely causes are electrical faults in the fuel pump control circuit, but the pump itself can also be involved.

Fuse

Blown fuel pump fuse

A blown fuse can leave the fuel pump circuit open and stop pump operation.

Relay

Faulty fuel pump relay

A relay that does not switch can stop voltage reaching the pump.

Pump

Failed fuel pump

A pump can fail internally, stop drawing current or stop responding to command.

Wiring

Open circuit wiring fault

Broken wires, rubbed looms or damaged insulation can interrupt the pump circuit.

Connector

Corroded pump connector

Loose pins, water ingress or corrosion at the tank/pump connector can cause intermittent faults.

Ground

Bad fuel pump earth

A poor ground can stop the pump circuit completing properly.

Module

Fuel pump control module fault

Some vehicles use a module to vary pump speed or control pump output.

ECU

ECU command issue

Less commonly, the ECU may not command the pump relay or module correctly.

Security

Immobiliser or crash cut-off issue

Some vehicles disable the fuel pump after security faults or impact events.

Severity

How serious is P0627?

Low

Code stored only, engine starts normally, fuel pressure is correct and no drivability symptoms.

Medium

Intermittent hard starting, occasional hesitation, related lean codes or fuel pump control fault pending.

High

No-start, cutting out, no fuel pump prime, low fuel pressure, stalling or fuel pump circuit dead.

Can you drive?

Can you drive with P0627?

You should be careful driving with P0627. If the car starts, runs normally, has normal fuel pressure and no cutting out, a short journey to a garage may be possible.

Do not drive normally if the engine is cutting out, cranking but not starting, losing power, hesitating badly or showing fuel pressure problems. A fuel pump control circuit fault can leave you stranded suddenly.

✅ Safe for short garage trip: starts normally, no cutting out, no hesitation and fuel pressure is correct.

⚠️ Diagnose soon: intermittent hard starting, stored P0627, occasional hesitation or related lean codes.

🚫 Recovery may be needed: no-start, no fuel pump prime, stalling, low fuel pressure or cutting out while driving.

Cranks But Won’t Start Car Won’t Start Diagnosis
Mechanic warning

Fuel pump circuit faults can stop the engine

Unlike some warning-light-only codes, P0627 can directly affect whether the engine receives fuel. If the circuit opens while driving, the engine may cut out.

If P0627 appears with P0171, P0300 or no-start symptoms, fuel pressure and pump control should be tested before driving long distances.

P0171 Lean Fault P0300 Misfire Diagnostic App
Typical UK repair costs

How much does P0627 cost to fix?

Costs vary by vehicle, access, fuel pump location, wiring condition and local labour rate. Treat these as realistic UK guide prices.

Diagnostic scan and fuel pump test

Typical range: £60–£150.

Fuel pump fuse or relay replacement

Typical range: £20–£150+.

Fuel pump wiring repair

Typical range: £80–£400+ depending on access.

Fuel pump connector repair

Typical range: £80–£300+.

Fuel pressure test

Typical range: £60–£150+.

Fuel pump replacement

Typical range: £180–£700+ depending on vehicle and tank access.

Fuel pump control module

Typical range: £150–£600+.

ECU command diagnosis

Typical range: £120–£500+ before any module replacement.

Recovery if no-start

Typical range: £80–£250+ depending on distance and provider.

Repair Costs Guide UK OBD Fault Codes Hub
Diagnosis

How to diagnose P0627

A proper diagnosis should confirm whether the fuel pump is being commanded, whether voltage and ground reach the pump, and whether fuel pressure is actually present.

✅ Scan all modules and record related fuel, lean, misfire and no-start codes.

✅ Check if P0627 returns immediately after clearing.

✅ Listen for fuel pump prime at key-on where applicable.

✅ Check fuel pump fuse and relay operation.

✅ Check ECU command to the pump relay or control module.

✅ Check voltage at the fuel pump during prime and cranking.

✅ Check fuel pump ground and voltage drop.

✅ Inspect pump connector for corrosion, loose pins or water ingress.

✅ Inspect wiring near the tank, underbody and relay/fusebox areas.

✅ Check fuel pressure with a gauge or scan data where possible.

✅ Check immobiliser or crash cut-off status where relevant.

✅ Check related codes such as P0171, P0201 and P0300.

✅ Confirm pump failure only after power, ground and command checks pass.

Real experience

What I would check first

On a real P0627 fault, I would start by checking whether the fuel pump is actually receiving power and ground. If there is no pump prime, I would go straight to the fuse, relay, control module and pump connector.

Next, I would check fuel pressure. A pump may run but still fail to produce enough pressure. Equally, a pump may be silent because the circuit is open, not because the pump itself is definitely faulty.

Only after proving command, voltage, ground and wiring would I replace the fuel pump.

Car Won’t Start Diagnosis Cranks But Won’t Start Diagnostic App
Vehicles commonly affected

Which vehicles commonly report P0627?

P0627 is a generic OBD-II code and can appear on many petrol and diesel vehicles with ECU-controlled fuel pump relays, fuel pump control modules or monitored fuel pump circuits.

Ford

Can appear on models using monitored fuel pump relay or fuel pump driver module circuits.

BMW

May appear on models with electric fuel pump modules and ECU-monitored fuel delivery circuits.

Volkswagen Group

Can appear on Volkswagen, Audi, Škoda and SEAT vehicles with electric fuel pump control faults.

Audi

May be logged where fuel pump relay, control module or wiring faults affect fuel delivery.

Mercedes-Benz

Can appear on vehicles using ECU-controlled fuel pump modules or relay-controlled fuel supply.

Other manufacturers

P0627 can also appear on Vauxhall, Peugeot, Citroën, Nissan, Toyota, Hyundai, Kia and other OBD-II vehicles.

Common mistakes

Mistakes to avoid with P0627

P0627 can become expensive if the pump is replaced before the circuit is tested.

Replacing the pump too quickly

A blown fuse, relay fault or open wire can stop a good pump working.

Not checking fuel pressure

Electrical testing and pressure testing should work together.

Ignoring pump ground

A bad earth can make the pump circuit behave like it is open.

Ignoring corrosion

Pump connectors near the tank can suffer water ingress and corrosion.

Only scanning the engine ECU

Some fuel pump control modules or body modules may store useful related faults.

Clearing the code before testing

Freeze-frame data and related codes can show when the circuit opened.

MOT impact

Will P0627 fail an MOT?

P0627 itself is not normally the direct MOT failure item. The MOT concern is what it causes. If the vehicle will not start, cuts out, has an engine management light, fuel leak, poor running or unsafe behaviour, it can affect the MOT.

A car with a serious fuel pump control fault may not even make it to the test centre. If it stalls, refuses to start or has fuel pressure problems, repair it before the MOT.

⚠️ Higher risk: no-start, cutting out, fuel smell, engine light, poor running or unsafe fuel system fault.

⚠️ Medium risk: intermittent hard starting, stored P0627 or occasional hesitation.

✅ Lower risk: fault repaired, normal fuel pressure, no warning lights and no drivability symptoms.

Engine Light MOT Guide Common MOT Failures
Fuel delivery reliability

Why fuel pump faults matter before testing

Fuel pump control faults can stop the engine suddenly or prevent the vehicle starting. That makes P0627 more serious than a simple stored warning code.

If the fault is active, diagnose it before long journeys, MOT testing or selling the vehicle.

Car Won’t Start Diagnosis Fault Codes Hub
Used car buying advice

P0627 on a car you want to buy

If a used car has P0627 stored, be cautious. It may be a simple relay or wiring fault, but it may also mean the fuel pump or fuel pump control module is failing.

Before buying, check whether the car starts cleanly from cold and hot, whether it cuts out, whether fuel pressure is correct and whether related lean or misfire codes are stored.

✅ Ask for a full diagnostic report, not just a cleared code.

✅ Check for P0171, P0201, P0300 or no-start related codes.

✅ Start the car several times during viewing.

✅ Road test under load if safe and legal.

✅ Be cautious if the seller says it only needs a relay without proof.

✅ Budget carefully if fuel pump or wiring diagnosis is needed.

Used Car Buying Guides Inspection Checklist
Negotiation warning

Do not ignore intermittent no-start faults

A car may start fine during viewing but fail later if the pump circuit fault is intermittent. That makes P0627 an important bargaining point.

If the vehicle has already cut out or failed to start, do not treat this as a minor code.

Buying With Advisories Check MOT History
Frequently asked questions

FAQs about P0627

Common questions about P0627 fuel pump A control circuit open faults, safe driving, no-start symptoms, repair costs and MOT impact.

What does code P0627 mean?

P0627 means the ECU has detected an open circuit in the fuel pump A control circuit.

Is P0627 serious?

Yes. It can cause no-start, cutting out, low fuel pressure or poor engine performance.

Can I drive with P0627?

Only if the car starts and runs normally with correct fuel pressure. Cutting out or no-start means do not drive.

Does P0627 mean the fuel pump is faulty?

Not always. The relay, fuse, wiring, connector, ground or control module can also cause this code.

Can a relay cause P0627?

Yes. A faulty fuel pump relay can leave the control circuit open and stop pump operation.

Can bad wiring cause P0627?

Yes. Broken wiring, corrosion or loose pump connector pins are common things to check.

Will P0627 fail an MOT?

It can affect an MOT if the vehicle will not start, cuts out, runs badly or has an engine warning light.

Can I clear P0627 without fixing it?

You can clear it, but if the open circuit remains, the code will return and the fault may continue.

How much does P0627 cost to fix in the UK?

Diagnosis may cost £60–£150. Relay repairs can be cheaper, while fuel pump replacement can cost £180–£700+.

What should I check first?

Check the fuel pump fuse, relay, pump command, voltage at the pump, ground and fuel pressure.

About this guide

Written for practical UK fault finding

Motor Vehicle Expert explains diagnostic trouble codes in clear, mechanic-style language for UK drivers. This P0627 guide is designed to help you understand fuel pump A control circuit open faults, likely causes, safe driving advice, repair costs, MOT risks and used-car buying concerns before replacing expensive parts.

Fault codes should always be treated as a diagnostic starting point. P0627 can involve the fuel pump, relay, fuse, pump wiring, pump connector, fuel pump control module, ECU command, immobiliser status, crash cut-off logic and fuel pressure. Proper testing is better than guessing.

For the full fault-code library, always start with the indexed OBD Fault Codes Explained UK hub.