What are the reasons for the yellow light on a China V diesel engine?

[SanCecilia]

The reasons for the yellow light on a China V diesel engine are as follows: Oxygen sensor failure: If the oxygen sensor is damaged or the sensor plug is damaged or loose, it can cause the mixture to be too lean or too rich, triggering the fault light. Spark plug carbon buildup: Excessive carbon buildup can cause the ignition coil to reverse breakdown, leading to ignition coil failure, poor ignition, and incomplete combustion. At this time, the fault light will also illuminate. Engine misfire: Engine misfire is also accompanied by the following symptoms: high fuel consumption, black smoke, weak car acceleration, severe shaking, and increased noise. The fault light will also come on at this time.