Gas Cap Light Warning On Jeep: Common Causes and Fixes

Gas cap light warning on Jeep is a worrisome problem that most Jeep drivers experience.

The main purpose of the warning is to alert the driver of a loose or cracked gas cap, but some other issues can also trigger the light on the dashboard. Read on to detect your Jeep’s problem and know how to fix it!

Why Does the Gas Cap Light Warning Come On in the Jeep?

The gas cap light warning comes on in the Jeep if the gas leaks because of a loose, broken, or dirty fuel cap. Leakage or a fault in the evaporative emissions system can trigger the gasoline cap alert. Moreover, a technical glitch in your car’s diagnostic system activates the warning.

• Missing or Split Gas Tank Cap

The check gas cap warning indicates that the cap on your fuel tank is not tight. It does this because it gets signals from the pressure sensor that detects fuel leakage. Since the tank loses pressure when the cap is missing, split, or cracked, the warning will appear.

One of the following reasons may explain the missing gas cap Jeep Wrangler:

• Mishandling of the fuel filler neck or a problem with the fuel tank cap assembly
• Forgetting to put it back after fuel refill or accidentally falling off the car
• Worn-out or loose cap falling off the car while driving
• Stolen for resale

Apart from a missing cap, a broken or split gasoline cap also triggers the warning on the dashboard.

The cap may break due to the following reasons:

• Long-term exposure to sunlight or heat dries the cap material and causes it to crack
• A vehicle hitting on the car’s side with the cap or other impacts
• Manufacturing defects or using a wrong-sized cap
• Abrupt temperature changes break the fuel lid
• Overtightening or aggressively turning the cap

You should never ignore a missing or broken gasoline cap. Firstly, it will be heavy on your pocket because of frequent refills. Secondly, gasoline fumes are hydrocarbons that escape into the air and worsen the air quality.

• Insecurely Fastened Gasoline Cap

If the cap is present on the tank opening and it does not look broken, you should check if it is tight. A loose or improperly threaded cap will allow the fuel to leak, and the pressure will drop inside the tank setting off the warning.

There can be many reasons for a loose cap. Sometimes people engage in conversations while filling the gas, so they might get distracted or forget to tighten the cap. You can also forget it if you are in a hurry.

Sometimes people notice a loose fuel tank cap because it wears out after its limited life. Moreover, the car vibrates a great deal while driving and can slowly loosen the cap.
Another common reason for a loose cap is foreign objects, dirt, or debris stuck in the cap or filler neck. Over time, the cap may get clogged due to dirt, so it will not sit perfectly on the filler’s neck. The foreign objects create gaps for the leakage of fuel.

• Leakage in Evaporative Emissions System

There might be a leakage in the Evaporative Emissions (EVAP) System if the Jeep gas cap light stays on after tightening the cap. The EVAP system regulates vehicle emissions to maintain air quality. The system works by controlling or capturing the leaking or evaporating fuel vapors.

The EVAP system operates when all its components do their job. These components may develop leakages because of reasons that lead to low fuel pressure. It activates the fuel cap indicator on the dashboard.

The following issues can cause an EVAP leakage:

• Damaged EVAP seals or gaskets
• Old or brittle rubber hoses in the EVAP system
• Poor EVAP component quality, design flaw, or unfitting assembly
• Ruptured fuel filler neck that connects the cap area to the fuel tank
• Cracks in the EVAP components because of heat or chemical exposure
• Physical damage to EVAP components because of an accident or impact

 

• Malfunctioning EVAP Components

The EVAP system has many components, such as the canister, purge or vent valves, pump, hoses, and pressure sensor. If any of these parts fails, the control unit will send a gasoline cap alert to the dashboard to show you something is wrong with the gas control system.

The bulleted list below shows all the possible malfunctions in the EVAP system:

• A saturated evaporative canister: The canister stores the fuel vapors before they enter the engine. It contains charcoal layers that absorb the vapors unless the engine draws them to burn. An old canister will get saturated or clogged with fuel vapors and debris reducing its absorbing capabilities.
• A damaged purge valve inhibits the flow of vapors to the engine: The purge valve creates a flow of fuel vapors toward the engine by opening and closing. A damaged valve will stay open or closed when it should not, hindering the fuel transfer.
• Canister pressure imbalance because of a failing vent valve: The valve opens and closes to allow air inside the canister creating an appropriate pressure. When it fails, the EVAP system alerts about the fuel tank cap issue.
• False leak detection because of a defective leak detection pump
• Loose or damaged EVAP component electrical connections
• False signals from faulty emission control sensors

If one of these issues exists, a Jeep gas cap light reset will be useless unless you repair or replace the malfunctioning EVAP component.

• Technical Glitch in the Car’s Diagnostic System

If you are still trying to detect the cause of the alert, you should consider a computer system glitch. Although not common in modern cars, there is still a possibility of a malfunctioning onboard diagnostic system (OBD).

The OBD system monitors your Grand Cherokee’s operations, including the EVAP system. OBD issues, such as a software glitch can produce a false gasoline cap alert. Usually, resetting the system can fix the problem; for example, the 2010 Jeep Wrangler gas cap light reset.

How To Fix the Gas Cap Light Warning in Your Jeep?

You can fix the gas cap light warning in your Jeep by cleaning and tightly screwing the fuel lid. If the warning still persists, you can reset the gasoline cap light with an OBD scanner. However, if the check engine light also glows, you should hire a mechanic.

• Tightly Screw on the Gas Cap

The first step in resolving the issue is to tighten the cap by turning it clockwise. You should keep turning until it clicks to ensure there is no leakage.

Turn off the engine and unlock the gas tank door. You can unlock it through the button under the driver’s seat. If the cap looks dirty, wash it and dry it with a cloth. Then put it on the fuel filler neck in a way that it sits perfectly and screw it in.

You can buy a new cap if the old one is loose or cracked. These caps come for around $10 to $50 each, depending on the type and quality, but OEM caps may cost more.

• Troubleshoot With an OBD Scanner

If the warning does not go away after tightening or replacing the fuel lid, you can reset it. Now you must be thinking about how to reset Jeep Cherokee gas cap light, so

here is how the 2015 Jeep Cherokee gas cap light reset works:

1. Disconnect the battery for a while to reset all your car settings.
2. Use an OBD-II scanner tool to specifically reset the fuel tank cap setting.

Although both methods can solve the problem, battery disconnection will remove all prior settings. For example, the radio or air conditioning modifications you made will be reset, so you will have to reconfigure them.

An important thing to consider is that you should only go for a reset if the engine malfunction light does not illuminate on your dashboard. An engine malfunction light indicates serious fuel issues, so ignoring them and resetting the cap message light will not fix anything.

If the check engine light is off, follow the steps below to reset the light:

• Find the OBD-II port under your Jeep’s dashboard or steering column.
• Turn on the ignition without starting the Jeep’s engine and press the reset button for a few seconds.
• The gasoline cap alert light will reset, so you can test your Grand Cherokee or another Jeep by driving it for some time.

 

• Hire a Professional Help To Fix the Fuel Cap Issue

If you have tried everything mentioned above and still have no luck, you should contact professionals to diagnose the faulty part. Tell them you tried the 2013 Jeep Wrangler gas cap light reset but it was useless.

 

An inspection may cost around $100. The mechanic can also fix the flawed part after diagnosis, so you should be prepared to pay the repair cost.

Conclusion

Now that you have the answer to why the gas cap light warning comes on in your Jeep, you can detect your Jeep’s alert issue and fix it. The main points that can help you get rid of

the light on the dashboard are as follows:

• A loose or cracked fuel lid leads to fuel vapor leakage, lowering the pressure in the fuel tank.
• Leakage or defects in EVAP system parts, such as the canister or valves, also activate the check fuel cap light.
• You can resolve the ongoing issue by tightening the cap or resetting the light.

These suggestions can help you with the 2012 Jeep Wrangler gas cap light reset or any other Jeep model.