DTC 5151? I removed the ride height level sensor?

2010 MERCEDES BENZ R350
342,466 MILES • V6 • 2WD • AUTOMATIC
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BLESSING EWOBOR
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Hello, I am working on a vehicle, the vehicle air spring is not functioning. When the vehicle was scanned, a DTC 5151(refer to service manual) was displayed. I removed the height level sensor, it has three with on the connector, when I probe the wires, the voltage was 1.074V. I think the reference voltage should be 5V, if I am right.
What could have been the cause?
Could I have a circuit diagram for it?

Thank you very much for your support so far.
Nov 27, 2024 at 9:47 PM
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You are correct, there should be a 5-volt reference signal supply line. There are 3 fuses that run the system here is the wiring diagrams so you can see how the system works and which fuses to check.

Diagnostic Trouble Code (DTC) 5151 indicates an issue with the Rear Axle Level Sensor (B22/3), specifically a "signal implausible" error.

Here is the location of the right rear level sensor so we can be on the same page. Check out the images (below). Please let us know what happens.
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Nov 28, 2024 at 12:45 PM
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BLESSING EWOBOR
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Thank you very much.
Nov 28, 2024 at 8:47 PM
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Use 2CarPros anytime, we are here to help. Please tell a friend.
Nov 29, 2024 at 10:41 AM
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Hello, I have checked the fuses and they are in good condition. I probe the module terminals while the engine is running, the powers and ground are available at the module but provide the reference voltage terminal, it is not up to 5v but 1.047 volt. Is it that the ECU is bad?
Nov 30, 2024 at 12:28 PM
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I would disconnect all ride height sensors and check it again, if one of them is shorted it will bring down the reference voltage. Also, I would check the grounds of the level control module.
Nov 30, 2024 at 2:48 PM
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The ground of the module is very okay.
Nov 30, 2024 at 6:13 PM
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Did you disconnect the sensors and re-measure the voltage?
Dec 1, 2024 at 10:22 AM
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Hello,
The air suspension problem has been resolved after replacing the Airmatic ECU. It is working perfectly okay now.
Thank you
Jan 15, 2025 at 8:57 PM
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Glad you could get it fixed, thanks for letting us know. Please use 2CarPros anytime we are here to help.
Jan 16, 2025 at 9:40 AM