What is the reason why the diesel engine fault light is on?

1. Intake pressure temperature sensor is damaged.

Cause analysis: the intake pressure signal is abnormal, and the ECU can't receive the correct intake information, which leads to abnormal fuel injection, so the combustion is insufficient, the engine is jammed, and black smoke is emitted when refueling. This fault can be caused by a harness connection problem and a sensor failure.

2. The water temperature sensor is damaged

Cause analysis: When the water temperature sensor fails, the ECU uses the substitute value when it detects that the output signal of the water temperature sensor is not credible, and the ECU limits the torque of the engine for the purpose of protecting the engine.

3. The oil pressure sensor is damaged

Cause analysis: the probe of the oil pressure sensor is seriously damaged, and ECU detects that the oil pressure sensor is not connected, and the instrument display value is the substitute value of ECU.

4. The harness of NOx sensor is short-circuited.

Cause analysis: The harness of NOx sensor is worn, short-circuited and grounded, and the NOx sensor can't work normally, resulting in excessive emissions, limited engine torque and system alarm.

5. The post-treatment heating relay box is damaged.

Cause analysis: wire harness open circuit fault.

Extended data:

Treatment plan:

No matter what causes the engine fault light to light up, it is necessary to use a computer tester for diagnosis. If it is a false fault code, just clear it directly. If it is a real fault, it needs to be checked and repaired according to the fault code. If only the engine fault light is on, the car is driving normally and there is no obvious abnormality, you can continue driving, but there is still time to go to the 4S shop for inspection; If the water temperature is too high or the oil pressure warning light is on, you can obviously feel the fault, or suggest getting off the bus for help.