What are the reasons for the Ford Focus warning light to come on?

[VanKylie]

Here are the reasons for the Ford Focus warning light to come on: Sensor issues: When the sensor is damaged, has poor contact, or experiences signal interruption, the car's ECU cannot accurately obtain engine data, which will trigger the engine warning light. Maintenance issues: Poor engine maintenance is a common cause of the engine warning light coming on. Oil quality issues: Failure to add engine oil as required will lead to engine wear over time, causing the warning light to illuminate. Poor combustion of the air-fuel mixture: Engine issues such as faulty spark plugs, defective ignition coils, malfunctioning fuel pumps, or clogged fuel lines can all lead to poor combustion of the air-fuel mixture. This poor combustion results in engine carbon buildup or knocking problems, thereby triggering the warning light.