After personnel arrive at the site, connect the decoder to read the fault code. There is only one fault code: p03ee, and the engine DPF lamp driving circuit is open. This fault should not affect the power. It is suspected that the DPF is blocked, but there is no corresponding historical fault and current fault. So first solve the current fault.
Check the cruise switch and relevant harness. The computer board is in the copilot. After inspection, it is found that k29 and K27 are not wired. It is suspected that someone has touched the harness before. Then, reconnect the lead of ECU pin to the DPF lamp, and the DPF lamp returns to normal.
Conduct the power test again. It is found that the fault is still there, and the engine idle speed will rise to 1000 rpm after driving for a period of time. The engine will occasionally shut down when going uphill, and the DPF light is always on and sometimes flashes. This goes back to the previous judgment. It is still the fault of DPF blockage.
There are only two solutions for DPF blockage, one is regeneration, and the other is direct replacement. Therefore, the DPF was regenerated in situ, but the regeneration was not successful. For better regeneration effect, the exhaust pipe is wrapped, but DPF still cannot be regenerated.
Since regeneration cannot be carried out, the DPF can only be replaced. When disassembling and inspecting the DPF, it is found that the internal ceramic body falls off. After replacement, the ECU is reset, regeneration can be carried out, and the fault of insufficient test drive power is solved.
Since the fuel injector belongs to the actuator on the engine, we can’t judge whether there is a fault inside the actuator by reading the data flow and action test with the decoder. This fault belongs to the mechanical fault of the fuel injector and can’t be checked with the diagnostic equipment. The reason why the water temperature is normal only when it reaches 70 ° C is that the needle valve and needle valve body of the injector are closed due to thermal expansion and the needle valve body is cracked, so the fault is eliminated after replacing the injector of the cylinder.
Since the fuel injector belongs to the actuator on the engine, we can’t judge whether there is a fault inside the actuator by reading the data flow and action test with the decoder. This fault belongs to the mechanical fault of the fuel injector and can’t be checked with the diagnostic equipment. The reason why the water temperature is normal only when it reaches 70 ° C is that the needle valve and needle valve body of the injector are closed due to thermal expansion and the needle valve body is cracked, so the fault is eliminated after replacing the injector of the cylinder.
Tips:
The treatment scheme for DPF blockage is relatively simple, which can be roughly divided into these stages: in situ regeneration (there is a regeneration button on the vehicle) – decoder regeneration – direct replacement.
However, there is an important knowledge. If it is necessary to reset the DPF after replacing the DPF, it is mainly to let the ECU know that it is a new DPF. ECU calculates the carbon loading to judge whether DPF needs regeneration, so ECU reset is very important and can not be ignored!
