Mercedes Benz E350 air suspension faults and troubleshooting

Mercedes Benz E350 air suspension faults and troubleshooting

Fault overview:
A 2010 Mercedes-Benz E350 executive sedan car with a mileage of about 118,000 kilometers. The car’s instrumentation often appears in the car’s suspension lift system alarm.

Eletronic Valve on air spring suspension for air spring suspension 2193201113 2113203138 repair Kits for Mercedes Benz W211

Eletronic Valve on air spring suspension for air spring suspension 2193201113 2113203138 repair Kits for Mercedes Benz W211

Troubleshooting:
Start the vehicle for a road test, and no fault alarm is found after the vehicle has driven for a certain distance. After parking, repeatedly press the suspension system lift button, the vehicle starts to lift normally. After several operations, a white alarm of the suspension lifting system suddenly appeared on the instrument. Connected to the diagnostic instrument to check the suspension lifting system, it was found that the equipment prompted the suspension lifting system control module to store fault code 5142, B22/9 (front right level sensor) signal distortion.
According to the fault diagnosis guidance of the diagnostic instrument, the actual signal voltage of B22/9 was measured first. When the suspension lifting system can lift normally, the signal voltage displays: signal 1 is 2.02V, signal 2 is 2.81V. When the lift fails, the voltages of measurement signal 1 and signal 2 are all displayed as 0V. The supply voltage of the B22/9 sensor should be measured according to the diagnosis guide. When the B22/9 sensor plug was unplugged, it was found that the plug had been severely rusted. It was preliminarily determined that the rust was caused by water entering when washing the vehicle.

Solenoid control Valve Block for Mercedes Benz W211

Solenoid control Valve Block for Mercedes Benz W211

When I was preparing to deal with the rusty plug, I accidentally pulled the plug by hand, and suddenly a stream of clear water flowed out, and water would continue to flow out of the line pipe. It seems that the rust at the plug is caused by the accumulation of water in the line pipe. The wire will get water into the plug due to the hair suction, which will eventually cause the plug to oxidize and corrode. Then use compressed air to blow in from one end of the line pipe to drain the dirty water. In order to prevent the plug from being corroded by water again, the author opened a small groove at the lowest part of the line tube. In this way, if water enters the line pipe again, the water can be drained from the small hole, and no water will accumulate in the line pipe again, thereby avoiding the plug from rusting again. After processing the connector thread and line tube, the fault reappeared in the re-installation test, and the fault code has changed from the original storage fault to the current fault, and the fault code still points to B22/9. So is the harness plug improperly handled or B22/9 damaged? The only way at this time is to measure whether the power supply voltage of B22/9 is normal from the back of the sensor plug. If the voltage is normal, the sensor is damaged. According to the circuit diagram (as shown in the picture), the technician measured the power supply of the sensor from the back of the B22/9 line and found that the power supply voltage of the sensor was 0V. Measured from the back end of the sensor plug, it is found that the power supply voltage between the 30th pin of the second socket of N51 and the third pin of the second socket is 0V. Continue to measure the resistance of the connection between the No. 3 pin of the second socket of N51 and the No. 5 pin of the sensor, which is infinite, which proves that the connection is open. Through the inspection of the relevant lines of the car, we can determine that the car has had an accident. After careful inspection of the collision point, it was found that the line was disconnected, the wire sheath connecting the wire was damaged, and the wire was completely disconnected. After reconnecting the wires, the test failure disappeared.

Air suspension electric valve for Mercedes W211 W219

Air suspension electric valve for Mercedes W211 W219

Fault overview:
A 2010 Mercedes-Benz E350 executive sedan with a mileage of about 118,000 kilometers. The car’s instrumentation often appears in the car’s suspension lift system alarm.
Troubleshooting:
Start the vehicle for a road test, and no fault alarm is found after the vehicle has driven for a certain distance. After parking, repeatedly press the suspension system lift button, the vehicle starts to lift normally. After several operations, a white alarm of the suspension lifting system suddenly appeared on the instrument. Connected to the diagnostic instrument to check the suspension lifting system, it was found that the equipment prompted the suspension lifting system control module to store fault code 5142, B22/9 (front right level sensor) signal distortion.
According to the fault diagnosis guidance of the diagnostic instrument, the actual signal voltage of B22/9 was measured first. When the suspension lifting system can lift normally, the signal voltage displays: signal 1 is 2.02V, signal 2 is 2.81V. When the lift fails, the voltages of measurement signal 1 and signal 2 are all displayed as 0V. The supply voltage of the B22/9 sensor should be measured according to the diagnosis guide. When the B22/9 sensor plug was unplugged, it was found that the plug had been severely rusted. It was preliminarily determined that the rust was caused by water entering when washing the vehicle.

N51 Air suspension Control module

N51 Air suspension Control module

When I was preparing to deal with the rusty plug, I accidentally pulled the plug by hand, and suddenly a stream of clear water flowed out, and water would continue to flow out of the line pipe. It seems that the rust at the plug is caused by the accumulation of water in the line pipe. The wire will get water into the plug due to the hair suction, which will eventually cause the plug to oxidize and corrode. Then use compressed air to blow in from one end of the line pipe to drain the dirty water. In order to prevent the plug from being corroded by water again, the author opened a small groove at the lowest part of the line tube. In this way, if water enters the line pipe again, the water can be drained from the small hole, and no water will accumulate in the line pipe again, thereby avoiding the plug from rusting again. After processing the connector thread and line tube, the fault reappeared in the re-installation test, and the fault code has changed from the original storage fault to the current fault, and the fault code still points to B22/9. So is the harness plug improperly handled or B22/9 damaged? The only way at this time is to measure whether the power supply voltage of B22/9 is normal from the back of the sensor plug.

If the voltage is normal, the sensor is damaged. According to the circuit diagram (as shown in the picture), the technician measured the power supply of the sensor from the back of the B22/9 line and found that the power supply voltage of the sensor was 0V. Measured from the back end of the sensor plug, it is found that the power supply voltage between the 30th pin of the second socket of N51 and the third pin of the second socket is 0V. Continue to measure the resistance of the connection between the No. 3 pin of the second socket of N51 and the No. 5 pin of the sensor, which is infinite, which proves that the connection is open. Through the inspection of the relevant lines of the car, we can determine that the car has had an accident. After careful inspection of the collision point, it was found that the line was disconnected, the wire sheath connecting the wire was damaged, and the wire was completely disconnected. After reconnecting the wires, the test failure disappeared.
Troubleshooting: Deal with the wiring harness.

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W220 W211 Maybach Suspension Compressor Wiring Harness

W220 W211 Maybach Suspension Compressor Wiring Harness

Fault summary: When the dashboard alarms, car owners should pay attention and go to the repair shop in time to check what caused it, otherwise it may affect other parts of the car and cause greater losses.

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