1. Damage to the intake pressure and temperature sensor:

①ON gear, the engine fault light is always on;
②A small amount of black smoke is emitted when the accelerator is stepped on the spot, and a lot of black smoke is quickly accelerated;
③The engine is sluggish;
④ Trouble code: P01D6 (the voltage of the intake pressure sensor is lower than the lower limit)
Reason analysis: The intake pressure signal is abnormal, and the ECU cannot receive the correct intake information. As a result, the fuel injection is also abnormal. The combustion is insufficient, the engine is sluggish, and black smoke is emitted during the refueling process. Problems with the wiring harness connection and sensor failure can cause this failure.
Solution: Check the intake air pressure and temperature sensor.

2. Damage to the water temperature sensor:

①ON gear, the engine fault light is always on;
②The water temperature in ON mode always displays the maximum value of 120℃;
③The engine has limited torque and is boring;
④Failure code: P003D (water temperature sensor voltage is lower than the lower limit)
Reason analysis: the water temperature sensor fails, and the ECU uses the substitute value when the output signal of the water temperature sensor is unreliable. The ECU limits the torque of the engine for the purpose of protecting the engine.
Solution: Check the water temperature sensor.

3. Damage to the oil pressure sensor:

①After starting, the oil pressure indicator light is always on;
②The engine fault light is always on;
③Idle speed, the oil pressure value is displayed as 0.99;
④Failure code: P01CA (the voltage of the oil pressure sensor is higher than the upper limit)
Reason analysis: the oil pressure sensor probe is seriously damaged, the ECU detects that the oil pressure sensor is not connected, and the value displayed by the meter is the substitute value inside the ECU.
Solution: Check the oil pressure sensor.

4. Poor contact of OBD socket terminals:

① In the ON position, the power supply of the diagnostic instrument is normal, but it cannot enter the ECU to read relevant information;
②There is no fault code.
Cause analysis: The OBD socket terminal exits, resulting in poor contact, and the diagnostic instrument cannot communicate with the ECU.
Solution: Check the OBD socket terminal.

5. Short-circuit phenomenon of the wiring harness of the nitrogen oxygen sensor:

①After starting, the OBD fault light is always on;
②The engine has limited torque and is boring;
③Fault code: P0050 (downstream nitrogen and oxygen sensor CAN signal receiving timeout), P018C (downstream nitrogen and oxygen sensor preparation timeout).
Cause analysis: the nitrogen oxygen sensor harness is worn out, short-circuited to the ground, and the nitrogen oxygen sensor cannot work normally, causing the emission to exceed the standard, the engine torque limit, and the system alarms.
Solution: Check the wiring harness of the nitrogen oxygen sensor.

6. Post-processing heating relay box damage phenomenon:

①After starting, the OBD fault light is on;
②Failure code: P028F (open circuit failure of heating relay control end of urea pressure pipeline).
Cause analysis: wire harness open circuit failure.
Solution: Check and repair the wiring harness of the heating relay box.

7. Open-circuit failure phenomenon of the drive circuit of the urea supply unit:

①After starting, the OBD fault light is always on;
②The engine has limited torque and is boring;
③Failure code: P3006 (open circuit failure of the drive circuit of the urea supply unit)
④Does not consume urea
Cause analysis: The urea pump control line is open. The specific manifestation is that the urea pump electrical connector is connected to the 10th pin, the urea pump does not work, and the system cannot normally inject urea, which causes the emission to exceed the standard, the engine is limited to torque, and the system alarms.
Solution: Check the connector at the end of the urea pump harness.

8. Phenomenon that the bottom software of the instrument does not send the speed signal:

①When going uphill or accelerating rapidly, the engine power will drop briefly for 1-2s; ②There is no fault code. Cause analysis: During driving, the vehicle speed signal sent by the instrument suddenly drops to 0, and the change of the vehicle speed signal causes the ECU to control the change of fuel quantity, resulting in an instantaneous fuel cut. Solution: If the part number of the instrument matched with the car is 3820010-61B, please update to the latest version of the instrument, the part number is 3820010D61B.

9. The phenomenon of blockage of urea return pipe in SCR system:

①After starting, the OBD fault light is always on;
②The engine has limited torque and is boring;
③Failure code: P0207 (SCR system urea return pipe blocked failure);
④Urea is not consumed.
Reason analysis: the debris in the urea return pipe is blocked, causing the system to fail to inject urea normally, the emission exceeds the limit, the engine is limited to torque, and the system alarms.
Solution: Check the urea return pipe (the urea pipe between the urea pump and the urea tank).

10. The phenomenon of crooked insertion of the connector terminals of the urea reflux heating pipeline:

①After starting, the OBD fault light is always on;
②Fault code: P0287 (open circuit or short-circuit fault occurs in the line between the load end of the urea return pipeline heating relay and the power supply).
Reason analysis: unplug the connector of the urea heating recirculation tube, it is found that the terminal is inserted crookedly.
Solution: Repair the terminal and reinsert the connector.

11. Trouble phenomenon of open circuit of urea pressure pipeline:

①After starting, the OBD fault light is always on;
②Fault code: P028E (open circuit or short-circuit to ground fault occurs in the line between the load end of the urea pressure pipeline heating relay and the power supply);
③In winter, the engine may be limited in torque and boring.
Reason analysis: the heating wire of the pressure pipe of the urea pump is broken, which causes the urea to be unable to be heated normally in winter, and the system alarms at the same time.
Solution: Check the pressure pipe of the urea pump (the urea pipeline from the urea pump to the urea nozzle).

12. Trouble phenomenon of open circuit of urea suction pipe:

①After starting, the OBD fault light is always on;
②Fault code: P029A (open circuit or short-circuit to ground fault occurs in the line between the load end of the urea suction pipeline heating relay and the power supply);
③In winter, the engine may be limited in torque and boring.
Reason analysis: the heating wire of the suction pipe of the urea pump is broken, which causes the urea to be unable to be heated normally in winter, and the system alarms at the same time.
Solution: Check the urea pump suction pipe (the urea pipeline from the urea tank to the urea pump).

13. Open circuit failure phenomenon of urea return line:

①After starting, the OBD fault light is always on;
②Fault code: P0287 (open circuit or short-circuit to ground fault occurs in the line between the load end of the heating relay of the urea return pipeline and the power supply);
③In winter, the engine may be limited in torque and boring.
Reason analysis: the heating wire of the return pipe of the urea pump is broken, which causes the urea to be unable to be heated normally in winter, and the system alarms at the same time.

Solution: Check the urea pump return pipe (the urea pipeline from the urea pump to the urea tank).

14. Urea leakage at the electrical connector position of the urea pump:

①After starting, the OBD fault light is on;
②The engine has limited torque and is boring;
③Does not consume urea; ④Fault codes: P0227, P0228, P01FC, P01FB, P02B1, P02A1, P01FA, P01FB (please refer to the maintenance manual for the corresponding information of the fault codes).
Cause analysis: urea leaks at the electrical connector of the urea pump, corrodes the metal pin, and causes a short circuit or open circuit fault in the circuit. (In severe cases, the rail pressure sensor will be burned out. The rail pressure sensor and the internal pressure sensor of the urea pump share the same power supply inside the ECU)
Solution: Check the electrical connectors of the urea pump and replace the damaged parts.

15. Open circuit phenomenon of exhaust temperature sensor wiring harness:

①After starting, the OBD fault light is on;
②The engine has limited torque and is boring;
③Does not consume urea;
④ Fault code: P027B (SCR catalyst upstream temperature sensor signal voltage is too high fault).
Cause analysis: the exhaust temperature sensor harness was worn off, and the ECU could not obtain the exhaust temperature upstream of the SCR catalyst, resulting in the urea pump not building pressure and not consuming urea, which led to excessive emissions, engine torque limit, and system alarms.
Solution: Repair the wiring harness and wrap it up.

16. The reverse installation of the crankshaft sensor and the oil metering unit connector:

① The maximum speed is limited to 1800rpm;
②The start-up time is too long;
③Failure code: P00EF (no signal from crankshaft sensor), P01E2 (pressure relief valve is opened).
Reason analysis: the crankshaft sensor and the oil metering unit connector are plugged in reversely, and neither can provide normal signals to the ECU.
Solution: Adjust the connectors of the crankshaft sensor and the oil metering unit.

17. Normal open phenomenon of antifreeze solenoid valve of urea tank:

The temperature of the urea tank is high, and urea is discharged from the vent plug of the urea tank.
Reason analysis: During driving, the antifreeze solenoid valve of the urea tank is always open, that is, the antifreeze has been thawing the urea tank.
①There are impurities in the cooling fluid, which are accumulated near the diaphragm, and the debris squeezes the diaphragm to form a pit, which affects the sealing;
②The operating pressure range of the solenoid valve does not match the actual pressure value. (The working pressure of the current solenoid valve is 20kPa～250kPa. The actual pipeline pressure may be lower than 20kPa. When it is lower than 20kPa, the diaphragm cannot be compressed and cannot be effectively sealed).

Solution: According to the parts catalog, change the solenoid valve assembly to the latest version.

18. The concentration limit of the calibrated nitrogen and oxygen sensor of the engine bench is too sensitive:

Russia’s J6 export car (common rail system) has the highest frequency of false alarms of nitrogen and oxygen sensors, and a large number of similar problems have occurred in the domestic common rail system:
①After starting, the OBD fault light is always on;
②The engine has limited torque and is boring;
③Failure code: P01FC: NOx peak check failure, P01FF: NOx increment check failure. Reason analysis: the calibration of the NOx concentration limit of nitrogen oxides is unreasonable, and the threshold is too sensitive. The peak calibration limit should be changed from 200ppm to 50ppm, and the signal variation range should be changed from 400ppm to 50ppm.
Solution: Flash the latest version data.

19. Permanent fault phenomenon of motor speed deviation of urea supply unit:

① The OBD light is on, no limit to twisting;
②Failure code: P02AB (permanent failure of motor speed deviation of urea supply unit).
Cause analysis: the urea pump motor is damaged.
Solution: Replace BOSCH 2.2 generation urea pump 1161010-51B.

20. Crystallization phenomenon at the urea nozzle seat:

The urea nozzle seat is uniformly crystallized, and the middle nozzle hole is not blocked and can be ventilated.

Cause analysis: There is a local swirling flow in the urea nozzle seat, causing a thin layer of urea crystals. Solution: It is a normal phenomenon, if it does not affect the emission, no treatment is required.

21. Crystallization at the air inlet of the post processor:

The air inlet of the post processor is uniformly crystallized, and there is no large crystalline urea.

Reason analysis: During use, a thin layer of urea crystals will be produced near the interface between the post processor and the intake pipe. Solution: It is a normal phenomenon, if it does not affect the emission, no treatment is required.

22. Phenomenon of the quality problems of the air intake control parts of the post processor:

① The OBD light is on;
②The vehicle is weak in torque limit;
③Urea is not consumed.
Analysis of the cause: The urea nozzle seat and the exhaust pipe are offset when they are welded, and “double eyelids” appear, which causes urea to crystallize and block the exhaust pipe.
Solution: Polish the “double eyelid” part.

23. Phenomenon of crystal blockage on the head of urea nozzle:

①After starting, the OBD fault light is always on;
②The engine has limited torque and is boring;
③Does not consume urea.
④ The head of the urea nozzle is crystallized and the nozzle hole is blocked.

Cause analysis: The angle between the urea nozzle seat and the exhaust pipe does not meet the BOSCH system engineering design specifications.
Solution: Replace the exhaust pipe in a new state.

24. The camshaft sensor connector is not inserted, causing difficulty in starting the engine:

①After starting, the OBD fault light is always on;
②The engine is difficult to start;
③Failure code: P0032—CAN B passive failure, P00EC—camshaft signal not detected.
Reason analysis: ①CAN B passive failure is a data problem and should be shielded; ②There is no camshaft signal, which makes it impossible to accurately determine the cylinder number when starting, making it difficult to start.

Solution: ①For P0032 failure, rewrite the latest version of the electronic control data released after September 2014 to shield the fault code; ②For P00EC failure, check the camshaft sensor connector.

 

 

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