There are many strange failure phenomena and different causes of failure; how to find the real cause of failure in the complex failure phenomena, I will tell you below.
Use the decoder to read the fault code p01db, which is the circuit fault code, so put the troubleshooting direction on the circuit and differential pressure sensor of ECU blindly.
Unplug the plug of the differential pressure sensor, measure the voltage at the female end, the voltage is 5V, 5V, and 0V respectively, and measure the connection and disconnection of the three harnesses at the same time. The connection and disconnection of the harness are normal; It indicates that there is no problem with the harness. It is suspected that there is a problem with the sensor of ECU blindly.
After replacing the POC differential pressure sensor, the fault remains. There is no problem with the harness and the sensor. Now I suspect there is a problem with the software or hardware of the ECU of ecu blindly.
After the program is written, the fault remains. It is planned to replace the ECU in the next step. Before replacing the ECU Hardware, use the decoder to read the data stream to see if other problems can be found.
No abnormality related to POC differential pressure sensor is found from the data flow.
The fault remains after replacing the ECU.
According to the fault code p01db – the particle trap POC differential voltage signal after-run is higher than the upper limit. After refers to the state after the T15 switch is powered off. It indicates that the measuring signal line is still energized after T15 is powered off.
Through the above troubleshooting steps, the ECU, harness and sensor are excluded. At the same time, the signal line voltage can be measured after the key is powered off, so it is suspected that there is a problem with the T15 harness.
For T15 flying wire