Late model vehicles such as the Jeep Cherokee utilize a system known as On Board Diagnostics, or OBD II, to optimize the performance of the vehicle’s emissions components. When one of these components fails, it will send a signal to the engine computer, which will trigger the check engine light in the dash. OBD II systems are extremely sensitive and can sometimes trigger without any real fault in the emissions system. If this is the case with your Cherokee, clearing the light is simple using a diagnostic code scanner.
Connect the diagnostic scanner cable to the vehicle’s diagnostic port. It will be located below the dash on the driver’s side of the vehicle.
Insert the key into the ignition and turn the key to the run position. Do not start the engine.