As far as warning lights go, the “check fuel fill inlet” light is one of the most prevalent error codes you’ll encounter while driving. Although the code can be triggered by a variety of problems, it’s usually nothing to worry about and can be fixed in a matter of minutes. That being said, though, it’s always best to stop and check every potential problem.
In most cases, a “check fuel-fill inlet” light indicates that your vehicle’s gas cap is either missing, damaged, loose, or too tight. If not, the warning light could indicate that debris has fallen into the fuel fill inlet. In some cases, it may also indicate that there’s an issue with the EVAP system, such as a leak in the fuel tank.
If you’re unsure of why your vehicle has issued a “check fuel fill inlet” light or you need help fixing the problem, continue reading to learn more. This guide will explain some of the most likely issues that can trigger the warning light and guide you through how to turn the light off.
Your Vehicle’s Fuel Cap is Likely to Blame
Before you do anything else, check to see if your gas cap is on tight. It may seem obvious, but many people forget to do this step. If it is loose, tighten the cap until you hear it click. If it’s too tight, loosen it until you hear the click. Be sure not to over-tighten or under-tighten the gas cap, as this can cause problems down the road.
Keep in mind that your vehicle’s fuel intake and EVAP system rely on a balance of pressure within the fuel tank. If the gas cap is too loose, fuel vapors will escape and trigger the “check fuel fill inlet” light. On the other hand, if the gas cap is too tight, it won’t allow the fuel tank to breathe and will also trigger the warning light.
If the gas cap is the problem, the “check fuel fill inlet” light should turn off within a few minutes after you’ve tightened or loosened the cap. If the light doesn’t turn off, there may be a more serious issue at hand.
Check for Debris in the Fuel Fill Inlet
If the gas cap is on tight and the “check fuel fill inlet” light is still on, the next step is to check for debris in the fuel fill inlet. Over time, dust, dirt, and other debris can fall into the inlet and cause problems, especially if you have capless fuel system. To check for debris, remove the gas cap and take a look inside. If you see anything visible, use a pair of needle-nose pliers to remove it.
If you cannot remove the debris with pliers, you can also try using compressed air to spray the debris away. Simply aim the can’s nozzle into the inlet and blast air until the dust or dirt is gone. If this still doesn’t work, you may have to visit a mechanic to have the inlet cleaned out
Pre 2014 Ford’s
This is a prominent issue with older Ford vehicles manufactured prior to 2014 that used a “Capless Fuel Filler” system. The problem is that the cap seal would often become contaminated due to poor design on some car models, leading it not to fully close, resulting in an EVAP leak. With the usual corresponding error code being P0442
Look for Signs of a Fuel Leak
If you’ve checked the fuel cap and the fuel fill inlet for debris and the check fuel fill inlet light is still on, there may be a fuel leak. A fuel leak can cause the “check fuel fill inlet” light to go off, as well as the check engine light.
To check for a fuel leak, park your vehicle on a level surface and inspect for drippage beneath the chassis. If you notice any fuel leaks, it’s crucial that you have them repaired immediately. Fuel leaks can be incredibly dangerous and should only be fixed by a qualified mechanic.
In some cases, a fuel leak can be caused by a loose or damaged fuel cap. If you’ve already checked the fuel cap and it’s not the problem, though, the fuel tank may be damaged and will need to be replaced.
Check the EVAP System for Leaks
If there are no signs of a fuel leak and the check fuel fill inlet light is still on, there may be a leak in your vehicle’s EVAP system. The Evaporative Emission Control System recirculates fuel vapors throughout the engine and, if the system is leaking, it won’t be able to maintain the necessary amount of pressure.
To check if your vehicle’s EVAP system has a leak, you’ll need to use a special EVAP system tester, which you can find at most hardware or auto part stores. Once you have the tester, follow the instructions to check for leaks in the system. If you find a leak, take your vehicle to a qualified mechanic immediately and have the leak repaired.
If you don’t have an EVAP system tester, you can take your vehicle to a mechanic or dealership and they can run a diagnostic test. This test will check for leaks in the EVAP system as well as any other potential issues.
Fixing the Problem
Once you’ve determined the cause of the check fuel fill inlet light, it’s time to fix the problem. If the light is on because the fuel cap is loose, damaged, or missing, the fix is simple: just tighten, replace, or add the cap. If the light is on because of debris in the fuel fill inlet, you’ll need to remove the debris and possibly clean out the inlet.
If there’s a fuel leak or a defect in the EVAP system, though, you’ll have to take your vehicle to a qualified mechanic. These systems are quite complex and, if they’re not working properly, can be incredibly dangerous. We don’t recommend trying to repair a damaged EVAP system or a leaking fuel tank on your own.
How to Replace a Broken Fuel Cap
If your gas cap is broken and won’t tighten into place, you’ll have to replace the part. Driving with a broken fuel cap can cause fuel leaks, reduced efficiency, and increased emissions. But, before you replace the part, you’ll have to remove it:
- Using a pair of pliers, twist the cap counterclockwise until it comes loose
- Pull the tether downward and unloop it from its housing
- If the tether is bolted in place, use a wrench to loosen the assembly
- If the cap is missing entirely, purchase a replacement from your local auto part stores
- To install the new fuel cap, start by lubricating the O-ring with a small amount of petroleum jelly. This will help create a tight seal and prevent future fuel leaks. Once you have lubricated the O-ring, twist the new fuel cap clockwise until it’s tight.
- Be careful not to over-tighten the cap, as this can damage the O-ring and cause fuel to leak. Then hook the tether over its housing or tighten the mounting bolt back into place.
Once the new fuel cap is in place, start the vehicle and check to see if the check fuel fill inlet light is still on. If it is, there may be a more serious problem and you’ll have to take your vehicle to a qualified mechanic.
The “check fuel fill inlet” light is a common error code that’s usually nothing to worry about. In most cases, it’s caused by a loose, damaged, or missing fuel cap. If you cannot find the problem, there may be an issue with your vehicle’s EVAP system or a fuel leak. If you can’t fix the problem on your own, be safe and take your vehicle to a qualified mechanic.