The diagnostic light will either be a warning light or an error light.
Warning lights indicate a problem with one of the vehicle's systems and should be fixed as soon as possible. If left unresolved, the warning light could result in a mechanical malfunction and/or premature failure of the associated system.
Error lights are typically indicative of data corruption on one or more files stored on your Ford Escape's hard drive and should be repaired as soon as possible. If left unresolved, this could result in lost data, crashes, and other potential problems.