Your inspect engine light, once it transforms on, is her Jeep"s method of letting you know that its on-board diagnostic system has actually detected a problem. Since the irradiate doesn"t give you lot information, the only method of identify why the irradiate is ~ above is to run a an easy diagnostic check.

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This article uses to the Jeep grand Cherokee WJ (1999-2004).

The check engine irradiate (CEL) doesn"t offer you lot information, however the five most typical reasons why the light come on in many vehicles encompass a faulty oxygen sensor, loose or faulty gas cap, faulty catalytic converter, faulty mass air flow sensor, or failing spark plugs and/or wires. Running a diagnostic will give you more information around why the light is on. This diagnostic tool, known as a code reader or scan tool, can also turn turn off the light, but unless you address and deal with the underlying issue, the light will certainly come on again after ~ you"ve driven in between 25 and also 50 miles. Utilizing the device is reasonably simple and also if you don"t have one, girlfriend can gain one at many auto parts stores.

Figure 1. The CEL alerts you the your Jeep"s on-board diagnostic system has actually detected a problem.

Method 1 – making use of an OBD scanner

Step 1 – find the data attach connector

The data attach connector (DLC) permits you to attach the OBD scanner to your Jeep"s ECU.

Make sure your Jeep is off prior to starting.Open driver"s side door and reach under the dashboard. The DLC is located on the much left side, towards the front and also slightly diagonal to the steering wheel.Figure 2. Situate the DLC.Step 2 – attach the diagnostic scannerPlug the scanner right into DLC and then rotate on your Jeep Cherokee.Figure 3. Attach the diagnostic scanner.Step 3 – run the diagnostic scanTurn ~ above the scanner and also go to the ideal screen because that diagnosing why her Cherokee"s CEL is on. The diagnosis might take a couple of minutes to totally run.When the diagnosis is complete, her scanner will certainly generate a list of codes details to what"s leading to the light to come on. If you"re not acquainted with the codes and also what they mean, your owner"s manual may include this information. Compose down the perform of codes the your scanner produced after perfect the diagnostic scan.Figure 4. Wait for scanner to pull up the CEL codes.Step 4 – Reset the inspect engine lightLeave the scanner connected to the DLC. The scanner will certainly ask if you want to erase all diagnostic results and codes. Choose "YES."Put your crucial in the ignition and also turn it come the "ON" position. Do not start the engine.Press get in on the scanner when you"ve done this. The scanner will connect with your Cherokee and tell it to turn off the CEL.Start the engine. The CEL have to now it is in off.
Figure 5. Check that you want it come reset the CEL.Figure 6. When computer system has been reset, the scanner will let you recognize the code has actually been cleared.

Method 2 – Without making use of an OBD scanner

Step 1 – Reset your examine engine lightDisconnect the confident (red) battery cable.Ground the hopeful battery cable to an adverse (black) battery cable for about 30 seconds.Reconnect the confident battery cable.Turn your crucial into the "ON" position, but do not rotate on the engine.Turn headlights on, and also leave lock on because that 10 come 20 seconds.Then rotate the headlights off.Turn your vital into the "OFF" position, and let the automobile sit for around one minute.Turn your key into the "ON" position, and also then begin your engine. The CEL have to now be off.

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Pro Tip

Resetting the examine engine light will not fix the worry that led to the CEL to which in the very first place. If you carry out not identify and also resolve the issue, the CEL will most likely come back on after you drive in between 30 and also 50 miles.