What Does The Check Fuel Inlet Light Mean? How To Fix

Are you seeing a "Check fuel inlet" light on your car's dashboard? Here's exactly what it means and how you can fix the issue.

A vehicle’s fuel fill inlet is the opening behind its fuel door, the area you stick the gas nozzle in when filling up at a station. Some fuel inlets are capless, like the Ford Easy Fuel system, which uses a spring-loaded flap valve to prevent fuel and vapors from escaping.

What does “Check Fuel Inlet” mean?

A “Check Fuel Inlet” dashboard warning light appearing means there’s a leak in your car’s evaporative emission control (EVAP) system. EVAP leaks commonly stem from loose or faulty gas caps. A malfunctioning flap valve or poorly sealed fuel door is the likeliest culprit with capless systems.

All cars have fuel inlets, but not all display a “Check Fuel Inlet” warning message when there’s an issue. Some simply prompt the check engine light, so you’ll have to use an OBD II scanner to reveal the fuel inlet as the culprit.

Regardless, the cause of the warning message is where your focus should lie.

In this guide, I’ll provide further details about the “Check Fuel Inlet” alert, including common causes, how to fix it, and more.

Let’s get started.

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Causes For The “Check Fuel Inlet” Dashboard Warning

Loose Or Faulty Gas Cap/Flap Valve

Fuel Cap

Whether your vehicle has a capped or capless fuel inlet system, they both keep gas from spilling out while also normalizing pressure inside the tank.

A loose or broken cap, worn fuel door seal, or faulty flap valve can easily allow gas and vapor to leak out, prompting the “Check Fuel Inlet” light.

Gas Tank Is Low Or Empty

Low Gas Tank

Little or no fuel in your gas tank can also lead to the “Check Fuel Inlet” light appearing. The reason involves low pressure inside the fuel tank, simulating an EVAP leak.

This is often caused by a loose or broken gas cap or one left open too long after filling up. Low pressure and a lack of fuel is the perfect combination for prompting the “Check Fuel Inlet” alert.

Poor Fuel Flow

Fuel Flow

Another issue that can illuminate the “Check Fuel Inlet” light is poor fuel flow. This typically stems from an issue with your vehicle’s fuel pump.

A fuel pump that isn’t drawing enough gas from the tank causes similar issues to a low or empty tank or a bad pressure sensor. The system may assume an EVAP leak and warn the driver via a dash indicator.

Bad Fuel Pressure Sensor

Fuel Pressure Sensor

Your car’s fuel pressure sensor (sometimes referred to as a fuel rail sensor), which is found on top of or inside the gas tank, may also light up the “Check Fuel Inlet” alert.

This sensor relays pressure data inside the tank to an ECU for use in the combustion air-fuel calculation. If it cannot send its readings, you’ll likely end up greeted by a dashboard warning light.

How To Fix The “Check Fuel Inlet” Warning Message

The first step is to remove your vehicle’s gas cap and inspect it for damage.

If the cap is not damaged, tighten it until you hear it “click” in place, then check if the dashboard message disappeared. If the cap is damaged, most reputable parts stores sell replacement caps for about $35 to $50.

Clean The Fuel Door And Inlet

Cleaning Fuel Door

With your car’s gas cap off, look around the fuel inlet and inside the fuel door, checking for any dirt or debris that might interfere with the seal.

Using a shop cloth, clean the inside of the fuel door and the inlet, but be careful not to let any debris fall in. Make sure to also wipe the inside of the gas cap.

Test The Intake And EVAP Systems For Leaks

If you’ve ruled out a bad cap, it’s possible there’s an intake or EVAP system leak. Thankfully, you can test both using an automotive smoke machine.

These devices do just as their name suggests, literally blowing smoke through the intake and fuel systems to help locate leaks. You can often rent smoke machines from local parts stores and shops.

Lubricate The Flapper Valve

For cars with capless fuel fill inlets, sometimes the flapper valve can get stuck or stiffen and needs to be manually lubricated and adjusted.

To loosen a stuck flapper valve, spray some WD-40 on it and, using the tip of a gas canister, repeatedly press on the valve, so it opens and closes. Do so 10 to 20 times, then check if the dash warning has disappeared.

Did Your “Check Fuel Inlet” Light Just Appear? Check Your Gas Cap And Fuel Door

In most cases, if the vehicle you’re driving displays a “Check Fuel Inlet” message on its dash, the gas cap is loose, or the fuel door isn’t fully shut.

If a quick trip to the rear of your car doesn’t solve the warning after 15 minutes or so, try out some of the other suggestions in this guide.

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Joshua Barrett

Josh Barrett is a writer hailing from the great state of Alaska. While describing himself in the third person is not his forte, writing about any and all things automotive – is. After 13+ years hustling in the exciting world of car sales, he took off to travel the world with his dog Teemo.