Audi A8L engine fault light, exhaust pipe black smoke.
  • Automotive

A Audi A8L3.0 car with a mileage of about 120 thousand km and a BDX engine equipped with a 01J transmission in 2009. Users reflect: the engine fault lights of the car are bright, and the exhaust pipes are emitting black smoke. Inspection and analysis: maintenance personnel use VAS6150B to detect engine control unit and no fault codes are found. The data block reflecting the adjustment state of the engine gas mixture is read, showing that the long-term fuel injection correction amount of the vehicle is + 22. 5%. Query fault guidance, the document gives the possibility of low pressure sensor too high. The inference is that the engine control unit may be able to control the oil pressure of the rail according to the wrong oil pressure data, resulting in abnormal oil pressure. After debugging the trouble code, the engine was observed to observe the value of the oil pressure sensor. It was found that it was normal at this time, but the engine was obviously shaking. It shows that the adaptive process of the engine control unit has not yet been completed. According to maintenance experience, the leakage of intake pipe or fuel injector will cause this phenomenon. When severe, fuel injection control will exceed the limit of fuel injection correction. Check the air tightness of the intake system without any problems. Remove the injector check and find that the injector is seriously blocked. It is believed that this is caused by the quality of the fuel. Troubleshooting: cleaning the injector, troubleshooting.