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

The fault causes of Pacific Auto Network are: 1, dirty throttle or self-problem; 2. Intake manifold pressure sensor problem; 3. The intake manifold behind the throttle leaks air; 4. Line problem; 5, engine control unit problems, etc.

A 20 10 Porsche Panamera sedan with a mileage of about 39000km. User feedback: The engine fault light will light up after the vehicle travels for a certain distance. The maintenance personnel found the fault as described by the user. Start the test run of the vehicle, the engine fault light will light up, and the instrument will prompt "engine maintenance". Therefore, diagnosis: ask the owner to know that the car was checked for burnt oil in 4S shop, and this fault occurred after the intake manifold was removed. The vehicle has not been modified in any way. Using diagnostic instrument WT to detect engine control system, there are two fault codes: one is P0068, the mass air flow is unreliable; The other is P 1074, where the mass air flow rate is too high under partial load.

Please refer to the explanation of this fault code. Description of fault code: If the air flow rate (MAF) calculated by the throttle position sensor (TPS) is lower than or higher than the limit value of the intake manifold absolute pressure (MAP) for 300 seconds, the engine control unit records the fault code P0068. The throttle position sensor (TPS) is located on the electronic throttle body and detects the throttle opening. The engine control unit determines the working states of idle speed, partial load, acceleration/deceleration and full throttle through TPS. Read the throttle position data stream, and no abnormal phenomena are found. Measure the vacuum with a vacuum gauge, and then calculate the intake manifold pressure. The numerical value is consistent with the actual value of intake manifold pressure in the data stream, which proves that the intake manifold pressure sensor is normal. Measure the signals of TPS 1 and MAPS with an oscilloscope, start the engine, and check the signal waveform when stepping on the accelerator. The waveforms of the two signals are normal and can rise and fall at the same time, indicating that the engine control unit has no fault.