Mercedes 212 Chassis - Fuel gauge

Bill Owner/Technician Michigan Posted   Latest   Edited  
Case Study
Electrical
2010 Mercedes-Benz E350 Sport 3.5L (272.980) 7-spd (7G-TRONIC)
Level Sender Faults Left And Right

Recently had a fuel gauge issue on this MB that i spent to much time on to diagnose... Figured I would share some info. 

Found faults P2228 & P2229 for level sensors stored in engine controller.

Check the rear SAM you can read resistance data for both sending units. ( Normal range is about 50 ohm Full to 900 ohm empty ) dont expect them to be exactly equal side to side.

Level sensor connectors can easily be accessed under rear seat. Rear SAM is mounted on left side of trunk. You can command a gauge test in instruments module to verify the gauge function.

In my case I substituted resistors of known value (250 ohm) into the circuit at both level sensor connectors and verified the rear SAM data matched. This proved my wiring between the module and sensors.

+1
Ray Diagnostician
Ontario
Ray Default
 

The P2228, P2229 are for the Baro pressure sensor A. But the same codes are for the fuel level sensors? Can you please explain.

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Bill Owner/Technician
Michigan
Bill Default
   

Ray - i have attached the fault code print out now, i dont know what happened in the translation/up load diag​.​net/file/f15lr5k4v… ​

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Ray Diagnostician
Ontario
Ray Default
 

Thanks Bill!

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