P0627 — Fuel Pump "A" Control Circuit /Open

P0627 — Fuel Pump "A" Control Circuit /Open. A fault in the fuel delivery and mixture control. Short, gentle driving to a shop is usually possible. Typical causes: weak fuel pump or clogged fuel filter, faulty fuel pressure regulator, contaminated or incorrect fuel.

powertrain (engine/transmission)

Is it safe to drive?

Drive with caution Drive with caution. Mixture and fuel-pressure faults can cause stalling, hesitation in traffic and — when severe — catalyst damage. Avoid long trips until diagnosed.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm P0627 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the fuel delivery and mixture control for damage, corrosion, chafing or poor contact.
Subsystem check Measure fuel pressure at the rail and compare with factory specification at idle and under load.
Subsystem check Check short-term and long-term fuel trims in live data to see which way the mixture is off.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P0627 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P0627 (parts and labor, USD, independent shop rates): Replace the pressure regulator or sensor: $150–$450; Clean or replace injectors: $200–$800; Replace the fuel pump: $400–$900; Replace the fuel filter: $80–$200. Overall, fixing P0627 usually costs between $80 and $900. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

How much does it cost to fix P0627?

Replace the pressure regulator or sensor — $150–$450; Clean or replace injectors — $200–$800; Replace the fuel pump — $400–$900; Replace the fuel filter — $80–$200. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

Will P0627 clear itself?

Sometimes P0627 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What are the symptoms of P0627?

Drivers most often notice: increased fuel consumption, hard starting or long cranking, rough idle and hesitation, Check Engine Light on.

What does OBD2 code P0627 mean?

Is it safe to drive with P0627?

Drive with caution. Mixture and fuel-pressure faults can cause stalling, hesitation in traffic and — when severe — catalyst damage. Avoid long trips until diagnosed.

When your check engine light pops up and a scan tool spits out P0627, the engine management system is telling you something specific: it cannot verify that the fuel pump control circuit is operating as designed. The powertrain control module (PCM) expects a particular voltage signal or feedback from the fuel pump driver circuit, and that signal is either missing entirely or outside acceptable range. In plain terms, the computer is asking the fuel pump to turn on or adjust its output, but it is not getting confirmation that the command was received or executed properly.

The fuel pump circuit on most modern vehicles works through a relay or a direct solid-state driver controlled by the PCM. When you crank the engine, the module energizes the circuit, fuel pressure builds in the rail, and sensors feed back data to confirm everything is running within spec. If that feedback loop breaks — whether due to an open circuit, a failed pump, a wiring issue, or a faulty driver in the module itself — the PCM logs P0627 and illuminates the warning light. It typically takes more than one failed attempt to set the code, which is why you might notice the problem intermittently before the light stays on. The stored freeze frame data captures engine speed, load, temperature, and speed at the moment of failure, giving you a starting point for diagnosis rather than chasing random symptoms.

Common Symptoms of P0627

The way P0627 affects your vehicle depends on how severely the fuel system is compromised. Watch for these signs:

Check Engine Light stays on or flickers during acceleration
Engine cranks longer than normal before starting, or fails to start altogether
Rough idle with noticeable hesitation when you rev the engine
Noticeable increase in fuel consumption compared to your normal driving patterns
Stumbling or flat spots during acceleration under load
Strong fuel odor inside the cabin or near the tailpipe, especially in more serious cases

What Triggers P0627

Several different problems can produce the same fault code. The most frequent culprits include:

A failed or failing fuel pump that cannot maintain adequate rail pressure
An open or shorted wiring harness, damaged connector, or corroded terminals in the fuel pump control circuit
A faulty fuel pump relay or control module driver that fails to complete the circuit
Problems elsewhere in the fuel delivery system that cause the PCM to detect abnormal pressure readings
Ground connection issues that prevent proper circuit completion
Aftermarket accessories or repairs that inadvertently disrupt the factory wiring

How to Diagnose P0627

Working through this code systematically prevents unnecessary part replacements. Follow these steps in order:

Connect your OBD2 scanner and confirm P0627 is stored. Record the freeze frame data — this snapshot tells you engine RPM, load, coolant temperature, and vehicle speed when the fault occurred, which helps you recreate the failure condition during testing.
Check for any other stored diagnostic trouble codes. Related codes — such as fuel pressure sensor faults or communication errors — often point to the actual root cause rather than assuming the fuel pump itself is bad.
Visually inspect the fuel pump wiring harness and all connectors in the circuit. Look for chafed wires, melted insulation near the pump, moisture intrusion, or loose terminals. A poor connection can mimic a failed component.
Test fuel pump operation directly using a fuel pressure gauge at the rail. Compare your readings against manufacturer specifications at idle and under load. Low pressure suggests pump, filter, or regulator problems; correct pressure points toward an electrical fault.
If wiring and pressure check out, verify power and ground at the fuel pump connector with a multimeter while the circuit is commanded on. No voltage or an open circuit reading confirms the problem is in the control side, not the pump itself.
Clear the code and complete a drive cycle that matches the freeze frame conditions. If P0627 returns, you have confirmed an ongoing hardware issue rather than an intermittent glitch.

Repair Options and Costs

Once you have isolated the faulty component, parts and labor costs at independent shops typically break down as follows:

Replace the fuel pump relay or control module driver: $150–$450 (parts $50–$150, labor 1–2 hours)
Clean or replace clogged fuel injectors: $200–$800 (injector cleaning $100–$250, replacement parts and labor $400–$800)
Replace the fuel pump assembly: $400–$900 (pump unit $250–$600, labor 1.5–3 hours depending on tank accessibility)
Replace the in-tank fuel filter or strainer: $80–$200 (filter $20–$60, labor 1–2 hours)

Most shops charge $75–$120 per hour for labor. The total repair bill for P0627 usually falls between $80 and $900 depending on which part actually failed. Starting with the least expensive possibilities — checking connectors, grounds, and the relay — before purchasing an expensive fuel pump can save you hundreds of dollars.

Can You Drive with P0627?

P0627 carries a caution severity rating. A malfunctioning fuel pump circuit can cause intermittent stalling, loss of power under acceleration, and rough engine operation that makes merging or navigating traffic hazardous. In severe cases, sustained fuel delivery problems can allow unburned fuel to enter the exhaust and damage catalytic converters. You should not ignore this code or plan a long highway trip until the fault is diagnosed and repaired. If the engine stalls repeatedly or loses power in traffic, have the vehicle towed rather than risk a dangerous breakdown.