No, the "Service Engine Soon" light (sometimes "Check Engine" light) doesn't automatically indicate a major problem. It simply means the car's onboard diagnostic system (OBD-II) has detected a problem that needs attention. This could range from something minor, like a loose gas cap, to something more serious, like a failing catalytic converter.
A scan tool is needed to read the diagnostic trouble codes (DTCs) stored by the car's computer. These codes pinpoint the specific issue. Ignoring the light could lead to more significant problems down the road, but the initial problem may not be catastrophic.
