Jeep Wrangler is showing the Check Engine Light but no codes

Well, it can be either a good or a bad sign. The good news is that it’s just a minor issue behind the check engine light.

As for the bad news, it could be that your engine has a serious problem only that your scanner isn’t good enough to reveal it. Read on to understand more about what we are trying to say:

Why A Jeep Wrangler May Show the Check Engine Light Without Codes

1. It Could Be a Poor Quality Scanner

There are numerous OBD-II scanners on the market whose manufacturers claim to be compatible with the Jeep Wrangler.

While these scanners will work with your Wrangler, some may not have full capabilities for your SUV as expected. These are usually poor-quality scanners that are incapable of running your car’s computer entirely.

This is especially if your Jeep model is a newer version with a newer computer.

2. It Could Be a Minor Issue

The scanner may not show a code if it’s a minor problem. This is especially if the check engine light is solid as opposed to blinking/flashing.

Remember that in Jeep Wranglers, the onboard code reader doesn’t often display a code for every problem. In that case, you need not worry much as the light will turn off after a few starts.

If it doesn’t, you should take your SUV to your dealer to have the code revealed. Some dealers offer this service to their customers for free.

Possible Solutions

If your Jeep Wrangler is showing the check engine light, but the OBD-II scanner is not showing a code, as said earlier, it could be that you are using a poor quality scanner or that it’s just a minor problem that will resolve on its own after some time. If it’s a substandard scanner, use your phone or laptop with the onboard computer instead.

Here’s how to do it:

  • Download good diagnostic software for the Jeep Wrangler onto your mobile or laptop.
  • Locate the OBD-II connection port of your car. It’s usually located above the pedals(brake, clutch & accelerator pedals) on the left or right, depending on whether your car has the steering on the left or right.
  • N/B: You’ll need an adaptor that helps you connect the port to your laptop. The OBDLink SX USB is a good one to use for this purpose.
  • It comes with two ends; one end is compatible with your OBD-II connection port and the other end plugs directly into your laptop’s USB port.
  • Once you connect your laptop to the ECM through this product(OBDLink SX USB), launch the software.
  • Select your car model, and year among other details that may be required.
  • Run the scan through the software and the ECM to reveal the error responsible for the check engine light.
  • If you are sure that the scanner isn’t the issue and that it’s just a minor issue that is causing the check engine light, give the light some time to resolve on its own. If it persists, here’s a quick DIY fix you can try;
  • Pop up the hood of your Wrangler.
    Go to the battery and remove the negative lead from it.
    Wait 15 minutes, then put it back onto the battery. If it’s not a serious problem, the light will resolve. But if the light persists, take your car to the dealer.

Can a Check Engine Light Turn Off By Itself?

Yes, it can, especially if it’s a minor issue. A good example is when your normal fuel pressure is disrupted due to what we call a “fuel slosh.”

Simply put, sloshing is the movement of gas inside the gas tank. A gentle slosh is fine. But a violent one can disrupt the correct fuel pressure in the engine, pissing off the ECM to react by causing the check engine light.

You may have this slosh during spirited driving or while cruising on a bumpy road. Once you get back to normal driving or moving on a smooth road, the movement of the fuel inside the gas tank will return to normal.

This will restore the normal fuel pressure thus calming the ECM and resolving the check engine light.


The check engine light of the Jeep Wrangler can sometimes illuminate your dashboard while your OBD2 scanner isn’t showing any error code. Usually, this happens for two reasons:

One: it’s just a minor problem with no significant impact worth an error code. This usually resolves on its own after some time. If not, you can make it go away by resetting the car battery as elaborated above.

Two: you are using a poor-quality scanner, which isn’t able to run all your ECM-generated error codes. In this case, you can use your laptop or mobile phone instead of the scanner to reveal the error code as explained above.

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