Jeep Wrangler Gas Cap Warning Light – [Reset]

There are several warning lights in a Jeep Wrangler triggered on the basis of an onboard diagnostic system including the gas cap warning light.

The gas cap serves as a lid to the fuel tank that supplies gasoline to the spark plug for igniting the Jeep engine. The gas cap protects the fuel tank from any type of contamination including dirt, debris, or smoke, and in case it gets loose or lost the diagnostic system senses the problem eventually popping up the gas cap warning light.

In this blog. I will walk you over with functions, reasons, and solutions to fix the gas cap warning light.

Also Read: Jeep Seat Won’t Recline? – [Here’s Quick Fix]

What does the Jeep Wrangler gas cap warning light mean?

The Jeep Wrangler gas cap warning light means that the on-board diagnostic system has detected some leakage, loose fitting, or a missing gas cap. If the warning light comes up, stop the Jeep on a safe pavement and inspect the gas cap. Give a couple of turns to the gas cap to fit it again and keep the light under observation. Also inspect the interior and exterior of the gas cap for any unusual smell.

If the warning light re-appears in a day or two, inspect for any cap leakage or hose leakage, or take it to the mechanic for resolving this issue.

Jeep Wrangler Gas Cap Warning Light

Functions of a gas cap

The gas cap plays a vital role in isolating the fuel tank from the environment and some of its functions include:

  • It ensures the vacuum pressure seal in the fuel chamber.
  • Pressurization smoothens the flow of fuel towards the engine.
  • It protects the evaporation of gasoline from the fuel tank thus maintaining the level.
  • The gas cap ensures that no outside element enters the fuel tank resulting in any contamination.
  • The rubber gasket around the fuel cap protects the fuel tank from the humidity that might lead to rusting or corrosion of the fuel tank.
  • Gas cap is an essential part of the EVAP system, protecting the travelers from inhaling toxic fumes.

Jeep gas cap light stays on-reasons

If the gas cap light doesn’t switch off after tightening or replacing the cap then you must inspect for the following issues.

1. Low battery

Several times, low battery is the issue for the triggering of these warning lights. When the battery grows older than two years, it results in key fob issues, flashing of warning lights and even troubles in Jeep start-up.

2. Vacuum leak

Vacuum leak results in harmful emissions from the EVAP system that may lead to the flashing of warning lights. Vacuum hoses are susceptible to leakage when posed to extreme heat conditions moreover the fuel tank exhibits corrosion in case of humidity.

3. Bad catalytic converter

Jeep possesses a catalytic converter that converts the carbon monoxide emissions into carbon dioxide. If there is any fault with the catalytic converter, fuel economy could suffer along with the popping up of the gas cap warning light.

4. Faulty mass airflow sensor

The mass air flow sensor maintains the quantity of fuel supplied to the throttle pedal. If the sensor suffers from any issue the gas cap light could trigger up.

How to fix a gas cap light Jeep Wrangler?

If the gas cap light flashes up, pull over the Jeep at a roadside and check the gas cap. In most of the cases the gas cap is loose or misaligned. Open the fuel tank flap, there resides a gas cap. Slip in your fingers inside and open the gas cap. Hold it in your hand and inspect it for any tear, crack, or rubber gasket wear. If there is no wear and tear just properly fit in the threads in the fitting area and wait for a clicking noise.

If the gas cap seems worn out or cracked, then a jeep cap replacement is a must. If there are no such issues but the gas cap warning light is still flashing, ask your mechanic to run a diagnostic check-up.

Related: GPS Not Working on Jeep Grand Cherokee? Here’s What To Do

Jeep Wrangler gas cap light reset

If the gas cap warning light still flashes after closing all the above issues, consider running an onboard diagnostic test with the help of an OBD-II scanner. There is an OBD-II port under the steering column, connect the scanner with it and run the diagnostic if there is no residing issue, push the reset button. It will drain all the false signals from the system.

Can I drive with the check fuel cap light on?

The fuel cap light doesn’t pose any immediate danger to the driver or passengers, but it is recommended that if the light pops up check the gas cap immediately. If the cap is missing or lose it will result in reduced fuel efficiency with time.

Moreover, in this case, the EVAP system fails, resulting in the deterioration of air quality inside the cabin. You will also notice the gasoline smell and reduced engine performance.

Also, due to the missing cap hydrocarbons will emit from the fuel tank resulting in the degradation of the environment and increasing carbon footprints.

Wrap up

Jeeps are known for their off-roading capability. Whether it is a Jeep Wrangler, Renegade, Compass, or Cherokee; they are known for their rugged and reliable driving abilities. Still, with time minor issues like gas cap warning or some other wear and tear could come up. So, make sure you attend these issues at your earliest and try resolving them with the DIY hacks mentioned in my blogs. If they don’t work for you, seek help from a professional expert.

Until next time, have a safe drive! 

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