Jeep Wrangler Check Engine Light: What It Means & How To Reset It

With all of the hardware and software coursing through the metal and rubber veins of vehicles these days, it would be more surprising if you didn’t have a check engine light on in your Jeep Wrangler. It may not mean anything and it may mean everything and, despite your misgivings, you should really check it out.

A check engine light is an indication that your PCM or ECM has detected a fault somewhere between the nose of your Jeep Wrangler and the tailgate. Getting rid of it is simply a matter of resetting the computer with an OBDII Sensor or pulling the battery cables for a few minutes.

If you are an amateur mechanic, meaning that you do your best to repair your own vehicle rather than take out a second mortgage on your home to pay a mechanic, you probably know what is or isn’t wrong with your Jeep. But it still pays to not ignore your check engine light.

What Could the Check Engine Light Mean?
OBDII Sensor
How to Reset the Check Engine Light
All Things Considered

What Could the Check Engine Light Mean?

The check engine light usually comes on when you first crank up your Jeep but that’s completely normal and it should go off again once the engine settles in. If it stays on, there might be a problem.

The longer you drive your Jeep, the more intimately familiar you will become with all of its subtle quirks and noises. If the check engine light comes on and there’s nothing that is otherwise wrong, as far as the sound and feel of the Jeep, it’s probably something minor.

If there is so much as a microscopic alteration in how the gasses flow through your catalytic converter, there’s a strong chance that it will trigger your check engine light. So it doesn’t always mean that your engine is about to drop out of the Jeep and go tumbling down the highway.

This is especially true if it’s just a solid, unblinking check engine light. If it’s blinking, you probably have something much more severe going on. If you catch your check engine light blinking on and off, you need to pull over somewhere soon, before you end up paying a tow truck.

If you live in a state that does annual emissions inspections, even a solid check engine light is bad news because it’s something that you’re going to have to pay for to make it go away. Otherwise, there’s a high probability that your vehicle won’t pass inspection.

OBDII Sensor

A check engine light is often enough to give you a feeling of absolute helplessness, assuming you don’t have an OBDII sensor sitting in your glove compartment. It could be that the engine light is nothing more than a loose gas cap.

But how are you supposed to know that your Jeep is not about to sling a rod if you can’t check it? Carrying an OBDII sensor in your glove compartment is one of the best moves you can make because they’re cheap as dirt if you stick with the basics.

If you already own a smartphone, which most people do, you don’t need any of that super expensive hardware to check the check engine light on your Jeep. With a standard OBDII sensor, all you need to do is plug it into the port that’s usually located beneath the steering wheel, close to the floorboard.

Once your OBDII scanner displays the code that your onboard diagnostics are screaming about, pick up your smartphone and Google the year and your Jeep Wrangler, along with the code on your scanner. Now you at least have a working idea of what’s going on under the hood.

Nowadays, you can even purchase OBDII scanners that link with an app on your smartphone, such as the FIXD. Or, you can just use BlueDriver, which is a bit more expensive but essentially the same thing with different features.

The point is, you are armed with knowledge now and knowledge is power. Right? If you don’t have an OBDII scanner, the first thing that the mechanic is going to do is hook your Jeep’s OBDII port to an expensive-looking tablet and then they’re going to charge you $50 just for the privilege of letting them do so.

That’s $50 out the window on a code you could have figured out yourself with nothing more than a $17.99 OBD2 scanner off of Amazon. In most cases, it’s probably something that you can pick up and replace yourself.

After all, paying fifty bucks for a crankshaft position sensor and installing it yourself is going to feel a whole lot better than paying $150 in labor charges, $50 for a scan, and sales tax.

How to Reset the Check Engine Light

Even if you are able to handle the problem on your own, that doesn’t mean the check engine light is going to go off on its own. You will have to reset it on your own and there are two ways to go about doing it.

Your OBDII scanner should come with an erase button or the erase option in the digital menu. Either way, all you have to do is plug it up and scroll to the erase tab or hold down the erase button until you’re given the option to confirm. Once you confirm, the check engine light will turn off from the dash.

If you want to turn it off the old-fashioned way, that’s pretty simple as well.

Turn the engine off and remove the key from the ignition
Pop the hood
Disconnect both battery terminals
Give it about five minutes
Reconnect the battery terminals
Turn the key in the ignition to the point just before cranking it up
The check engine light should be off

All Things Considered

A check engine light could mean absolutely anything. Most of the time, it’s probably not something to get panicky over. If it’s blinking, that’s a different story altogether. Get yourself an OBDII scanner and you will always have a go-to option sitting in the glove compartment.

It’s better to be informed than it is to be stranded on the side of the road with no idea what’s wrong with your Jeep.