What will be the problem if your service engine light come on a cadillac deville 2004?

If the service engine light comes on in a 2004 Cadillac DeVille, it indicates that the vehicle's onboard diagnostics system has detected an issue that needs attention. Common problems could include issues with the engine, transmission, emissions system, or other critical components. It's essential to diagnose the specific trouble codes using an OBD-II scanner to determine the underlying cause. Ignoring the light could lead to decreased performance, reduced fuel efficiency, or further damage to the vehicle.