The difference lies in *how* the light is triggered:
* Service Engine Soon: This is usually a less urgent warning light. It often comes on due to something relatively minor, like a loose gas cap, a failing oxygen sensor (that may still be functioning somewhat), or a minor issue that doesn't immediately impact drivability. It might also indicate that routine maintenance is due (like changing the oil).
* Check Engine (or Engine Icon): This typically indicates a more serious problem. It often signals a fault that could affect performance, emissions, or even safety. Things like a malfunctioning catalytic converter, a major sensor failure, or issues with the ignition system would usually trigger this light.
In short: While both point to a problem needing attention, "Check Engine" generally suggests a more critical issue than "Service Engine Soon." However, you should never ignore *either* light. Get the car diagnosed as soon as possible using an OBD-II scanner (or a mechanic) to determine the specific problem code. Ignoring these warnings can lead to more serious (and expensive) repairs down the road.
