Check engine light on 2004 jeep grand cherokee?

If the check engine light is on in a 2004 Jeep Grand Cherokee, it indicates that the vehicle's onboard diagnostics system has detected a potential issue. Common causes can include problems with the oxygen sensor, catalytic converter, or issues related to the fuel system. It's advisable to use an OBD-II scanner to retrieve the trouble codes, which can help pinpoint the exact problem. If you're unsure, consulting a professional mechanic is recommended for a thorough diagnosis and repair.