What causes the engine check light to turn yellow?

The reasons why the engine fault light turns yellow: 1. Sensor problem; 2. Poor mixture combustion; 3. Improper maintenance; 4. Poor fuel quality; 5. Engine cylinder shortage; 6. Engine overheating; 7 , Intake problem; 8. ECU system error; 9. Engine wiring or connector failure; 10. Catalytic converter failure; 11. Engine control unit failure; 12. Internal engine parts are worn or damaged; 13. Engine overload; 14. Emission control system failure; detailed introduction: 1. Sensor problems, including water temperature sensor and intake air temperature sensor, etc.

The engine fault light may turn yellow for many reasons. Here are some common reasons:

1. Sensor problem :Including water temperature sensor, intake air temperature sensor, oxygen sensor, etc. These sensors may be damaged, have poor contact or have their signals interrupted, causing the engine fault light to come on.

2. Poor combustion of the mixture: Engine spark plug failure, ignition coil failure, fuel pump failure, oil circuit blockage, etc. may cause poor combustion of the engine mixture, resulting in carbon deposits or Problems such as knocking will be detected by the engine's oxygen sensor. After being reported to the ECU, the fault light will light up as a warning.

3. Improper maintenance: Failure to change the oil or air filter in time, failure to maintain scheduled maintenance, bad driving habits, etc. will increase the burden on the engine and may cause the engine fault light to come on.

4. Poor fuel quality: Adding poor quality gasoline at non-standard gas stations will lead to insufficient combustion of the oil-gas mixture when the engine is working, and may also cause engine failure.

5. The engine is missing a cylinder: The ignition coil or spark plug is damaged, resulting in a cylinder missing, causing the engine fault light to come on.

6. Engine overheating: Long-term intense driving, insufficient coolant or radiator fan failure may cause the engine to overheat, causing the fault light to illuminate.

7. Air intake problem: The air filter element has not been cleaned for a long time, causing the air inlet to be blocked. In severe cases, it may cause engine failure and the fault light will come on.

8. ECU system error: ECU system failure or software error may cause the engine fault light to illuminate.

9. Engine line or connector failure: The engine line or connector may be corroded, vibrated or mechanically damaged, resulting in poor contact or signal transmission interruption, causing the engine fault light to illuminate.

10. Catalytic converter failure: The catalytic converter may fail due to blockage, damage, or excessive temperature, causing the engine fault light to illuminate.

11. Engine control unit (ECU) failure: ECU is the control core of the engine. It is responsible for receiving and processing various sensor signals and controlling the operation of the engine according to the preset algorithm. If the ECU fails, it may cause the engine to not work properly and the fault light to illuminate.

12. Wear or damage to internal engine parts: Internal parts of the engine, such as cylinders, pistons, crankshafts, etc., may be worn or damaged due to long-term use or improper operation, which may cause engine damage. Fault, the fault light comes on.

13. Engine overload: Long-term high-load operation or speeding may cause the engine to be overloaded, causing the engine fault light to illuminate.

14. Emission control system failure: Problems with the emission control system, such as three-way catalytic converter failure, oxygen sensor failure, etc., may also cause the engine fault light to illuminate.

In short, there may be many reasons why the engine fault light turns yellow, and it needs to be checked and diagnosed according to the specific situation. If you encounter this situation, it is recommended to contact professional maintenance personnel for inspection and repair in time.

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