How To Reset Jeep Wrangler Check Engine Light?

If your Check Engine light is on, it means that there’s something wrong with your engine. It’s a way of your engine trying to tell you to take care of it. Whenever it appears, you should check your engine.

But, that dreaded Check Engine light could be on for a lot of reasons. What if you know there’s nothing wrong with your engine, and the light is still on? That could be quite annoying, as I found.

Now, if you drive a Jeep Wrangler, you have to know how to reset Jeep Wrangler Check Engine light to fix it. Let’s check it out.

Why Could the Check Engine Light Be On in a Jeep Wrangler?

Even if you know that your engine is fine, you should know the reasons why your Check Engine could be on in your Jeep Wrangler.

Spark Plug

The spark plugs may have worn out. If they did, they’d be damaging the O2 sensors and the ignition coil. It may also create clogging in the converter.

Aftermarket Parts

If an aftermarket component isn’t correctly installed, it can cause a lot of issues. Battery draining or triggering the engine light is a common problem caused by a faulty aftermarket item. You could use OEM parts instead.

It can cost you a bit more, but you won’t have to run to a mechanic, every now and then.

Leak in the Vacuum System

The Check Engine light on your Jeep Wrangler will stay on if there’s a leak in the vacuum system.

The system controls the emission of toxic gases and lets them leave through the exhaust pipe. If there’s a leak in it, the Check Engine light will be turned on.

Loosened Gas Cap

There’s a gas cap on your Jeep Wrangler that serves a lot of purposes. The gas cap stops fumes when the engine isn’t on. It controls the pressure in the tank by sealing the fuel system.

If the gas cap is loose, the fuel will start to evaporate, and you’ll have less fuel efficiency. And, of course, the Check Engine light will be on if the gas cap isn’t properly sealed.

Dead or Low Battery

The Check Engine light on Jeep Wrangler could be turned on if your car has a low battery. It goes without saying that your car won’t even start if the battery doesn’t have enough power.

It might be running low, which could be enough to start your car, but isn’t enough to run it properly. This is when your Check Engine light will let you know that you need to fix the issue.

Faulty O2 Sensor

If the O2 sensor is faulty, your Check Engine light will be turned on. If you have an O2 sensor that isn’t working properly, you’ll have less fuel efficiency.

Also, it can even damage the spark plugs and the catalytic converter.

Faulty Catalytic Converter

Another reason why your Check Engine light could be on is because of a faulty catalytic converter.

It creates Carbon Dioxide from Carbon Monoxide. If it’s damaged, your car will use more fuel, and even fail in an emission test.

Problems in the MAF

The MAF or mass airflow sensor decides the amount of fuel your engine requires to run. If you have a faulty MAF, you can face problems in starting the Jeep Wrangler or a shift in the position of the throttle pedal.

Jeep Wrangler Error Codes

Your Jeep Wrangler is equipped with a PCM computer. PCM stands for Powertrain Control Module, which scans and detects any issues in your car.

The PCM in a Jeep Wrangler works through thousands of codes. When it finds any issue in the car, a trouble code or error code is sent to the PCM, which turns the Check Engine light on.

How to Bring the Error Codes on the Panel

Now, if you see that your Check Engine light is on, you want to know what’s wrong with your car. Before running to a mechanic, you can find it out yourself. Your Jeep Wrangler has an amazing computer; why not use it!

To bring the error codes on the panel, follow this procedure:

  1. Turn off your engine and close the car’s doors if any of them are open
  2. Put the key in the ignition and turn it on without turning the engine on
  3. Do it for 3 times and leave the key in “On”
  4. You’ll see your Odometer performing a reading, and the error codes will appear on the screen

If this process doesn’t work for you and you don’t see any error codes, then instead of turning the key to “On”, take it to the “ACC” position.

Jeep Wrangler No Codes on Check Engine

I’ve talked about the error codes and how you can pull them up on your panel. But, what if your Check Engine light is on, but there’s no error code?

Many users have reported this issue, and most of the time, the reason is bad fuel. Jeep Wrangler’s PCM is quite predictive, and it can detect a lot of issues that a lot of other cars can’t.

So, you could try taking fuels from a different station if you find your Check Engine light turned on, but there’s no error code.

There’s another reason you don’t see any error codes even if the Check Engine light is on. Your PCM has an OBD2 scanner that brings up the codes on your panel.

If you’ve got a faulty scanner, the no code issue on the panel might appear. So, try replacing the scanner and see if it works.

How to Reset Jeep Wrangler Check Engine Light

If you had your Jeep Wrangler checked and there’s no issue with it, but still, the Check Engine light is on, then you can try resetting it.

  1. Look for the battery terminal after opening the hood. Using a wrench, loosen the positive terminal’s bolt that’s attached to the clamp. Get the clamp out, and make sure it doesn’t touch the negative side. Wait for 1-2 minutes now.
  2. Put the clamp in the same place and seal the bolt tight using a wrench. Get in your card and insert the ignition key. Turn the key and keep it to “On” for 5-6 seconds. After you turn on the engine, you’ll see the Check Engine light flashing and going off.

Frequently Asked Questions

Should I Drive My Jeep Wrangler With The Check Engine Light On?

It’s not recommended to drive a Jeep Wrangler with the Check Engine light turned on. Evidently, it’s a sign that your engine is facing some issues. You could drive to a mechanic at most. However, if the light is still on after solving the problems, you can try resetting it or pull on the error codes.

Can Bad Fuel Cause My Check Engine Light To Turn On?

Yes, it can. It’s one of the main reasons why your Check Engine light could be on even after checking your engine.

Can The Check Engine Light In My Jeep Wrangler Reset By Itself?

Yes, it can. If there’s no issue with your OBD2 scanner or the PCM, after you’ve fixed the issue with your engine and drive for a few miles, the Check Engine light will reset by itself.

How Do I Identify If There’s Anything Wrong With The Computer In My Jeep Wrangler?

The Powertrain Control Module or PCM in your Jeep Wrangler is a complicated system that detects any issues within the car and sends error codes.
If there’s an issue with it, your Check Engine light might be turned on without any reason. Other than that, you’ll face difficulty starting the vehicle, and you’ll get less fuel efficiency.

Can I Replace The PCM In My Jeep Wrangler?

If you need to replace the PCM, the system itself would cost around $700-$750. Installing it would cost you around $50-$70.


Jeep Wranglers are fantastic vehicles for any terrain. People who’ve used them are quite happy with their performance. However, the PCM in the car is quite complicated, which might cause troubles that you can’t identify.

If your problem is seeing no error code or a turned “On” Check Engine light, knowing how to reset Jeep Wrangler Check Engine light will come in handy.

However, when your Check Engine light is on, the bottom line is that you’ve got to check your engine or run to a mechanic first if you don’t know much about it. Ignoring the issues of your engine might lead to severe troubles which you wouldn’t want.

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