Jeep Malfunction Indicator Light On – Causes

Jeep Malfunction Indicator Light On – Causes

You should take it seriously when the malfunction indicator light comes up. The indicator light cannot be mistaken.

It indicates something is wrong with the Jeep and alerts you to take action before things get out of hand.

Jeep malfunction indicator light on

When the light comes up in your Jeep, it may indicate a fault in the vehicle’s emission control system, transmission, or engine.

You should take steps to investigate the cause when the light comes up.

If you are a first-timer Jeep user, you may be confused about the appearance of the indicator light.

We will guide you here on what may be the problem when the MIL comes up. We will also enlighten you on how to resolve the issue.

What Does Malfunction Indicator Light Mean?

When the Malfunction Indicator Light comes up, it can signal three types of problems in the Jeep:

  • If the indicator light flashes occasionally, it indicates a temporary malfunction. The temporary issues may result in significant problems in the future. So, you must take the flashing seriously and resolve any issue causing it.
  • If the Jeep malfunction indicator light stays on continuously without blinking, it indicates serious problems with the car’s engine. Even if the issue is not that serious, it may negatively affect the vehicle’s emission. It would be best if you also took action immediately before it grounds the vehicle.
  • If the Jeep malfunction indicator light flashes every time, this signals the most severe problem. It means that the vehicle’s engine is misfiring. The problem may cause the car’s catalytic converters to overheat. It is a significant issue, and you should not drive the car further to prevent more severe damage to the engine. A fire incident may even occur.

The Jeep malfunction indicator light will usually illuminate for some seconds when you start the engine. It will, however, go off once the engine starts running.

The Causes

What causes the Jeep malfunction indicator light to come up could be a major or minor issue. You can only find out if you investigate.

The significant issues require an appropriate measure to be taken on time lest they ground the engine.

Just looking at the indicator light will not give you adequate information needed to detect the cause of the problem.

Check below for tips on detecting the cause of the Jeep malfunction indicator light coming on.

When the light stays on, it indicates that the oxygen sensor in the car is failing. The car may continue driving well like before, but you should find a solution to it fast.

You can confirm this by connecting the car to a diagnostic system. The diagnostic system will show an O2 sensor code, confirming the problem.

The Usefulness Of The Diagnostic Trouble Codes

Another name for the diagnostic system is the OBD2. It reads the Diagnostic Trouble Codes from the system, informing the car owner of the specific problems.

The OBD system shows a Diagnostic Trouble Code in its electronic control unit when it turns on the Jeep malfunction indicator light.

The Diagnostic Trouble Code will then provide information about the issues detected.

Once you resolve the problem, the OBD2 system will turn off the Jeep malfunction indicator light after resolving the issue responsible for it.

The OBD2 will equally evaluate the system three consecutive times. Failure to detect any problem will make the light remain off.

How To Resolve The Issue

You do not have to take your car to a mechanic before detecting what may cause the Jeep malfunction indicator light to come on.

You can detect it yourself if you have the OBD diagnostic software and the OBD2 scan tool. The readout from the tool will tell you how to resolve the issue.

It is equally easy to reset the MIL yourself since the tool eases the detection process.

Causes of Jeep malfunction indicator light on

Fixing the problem indicated by the OBD2 scanner depends on how much knowledge you have about the Jeep’s mechanical issues.

You can also check the vehicle’s manuals to find solutions to the problem. Jeep owners’ manuals contain information on how to resolve some engine issues.

If the issue requires that you dismantle the engine, on the other hand, you should contact a mechanic to do the job for you.

Forms Of OBD2 Tools

The OBD2 tools are of two forms: the free version and the paid version. The free version is helpful to an extent.

However, the paid version will give you all the features you require for the complete detection and resolution of the fault, causing the Jeep malfunction indicator light to come up.

For example, you can carry out live testing in the paid version and view live data. Such features are not accessible on the paid version.

The free version can read and clear the DCTs. You can access the OBD2 details on your laptop by connecting the two via a USB OBD2 cable.

You, however, need first to install the software on your computer before this can be possible. The free software does not work with a laptop.

The OBD2 scan tool can work as a standalone tool available at different prices. It can be as expensive as several thousand dollars and as cheap as a few dollars.

There is no need to invest thousands of dollars in the OBD2 scan tool before it can scan and resolve the Jeep malfunction indicator light coming on.

The cheap ones should give you the essential diagnostic functions.

Steps To Resolve MIT Light Using An OBD2 Scan Tool

  • First, turn off the car’s engine.
  • Plug the OBD2 scan tool into the DLC.
  • Then turn the ignition key to “On” without starting the engine.
  • Several options will appear on the OBD2 scan tool or your laptop screen.
  • Wait for a couple of minutes for the tool to connect to the ECM.
  • Activate “Erase Codes” or “Clear DTCs”. It may require a few seconds to respond.
  • Follow the specific documentation on the app or tool for instructions on how to resolve the issue.

If you follow the instructions in the letter, it will resolve the issue. The scan tool can then confirm if you handle the problem properly.

After the confirmation, you can turn the ignition “Off” and leave it for about 10 seconds. You can now start the vehicle and check if the light still stays on.

However, the steps above should resolve the issue, and the light should be off.

Hard Reset Is Essential

To carry out the hard reset of the engine, you will need to disconnect the battery in the engine. However, turn the engine off before you do this.

Once the engine is off, disconnect the negative terminal clamp of the battery. You can do this using a ½ inches socket or wrench.

Next, press the brake for a minute to deplete the energy in the capacitors. Remove your feet from the break and reconnect the battery.

The Hard Reset can work in your Jeep since its memory is voltage-dependent. The hard reset will clear the CEL and DCT, making the vehicle ready for action.

However, the vehicle may not be all right for a couple of days until the TCM and ECM relearn their fine-tuning.

Hard reset can cause the aftermarket alarm systems and some car radios to go into an anti-theft mode, requiring that you input specific codes before using the radio.