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How to change the Engine Oil Level Sensor on a Mercedes-Benz

Below you will find step by step instructions with pictures on how to remove and install a new engine oil sensor on a Mercedes Benz engine. Part numbers related to the oil level sensor are shown below and there could be more. The purpose of the the oil level sensor (B40) is to measure the oil level but also oil temperature and the oil quality. This E320 was showing “Reduce oil level” warning in instrument cluster even though the oil level was correct. Once we replaced the oil level sensor the error no longer displayed on our dash. These instructions apply to several Mercedes Benz models that have the V6 or V8 engines in them. Below is a list of models that these instructions apply to:


These instructions apply to Mercedes-Benz  models such as:

  • C240, C32 AMG, C320, C55 AMG, CLK320, CLK500, CLK55 AMG, CLS500, CLS55 AMG,
  • E320, E500, E55 AMG,
  • ML500, R500,
  • SL500, SL55 AMG, SLK55 AMG

YEARS: 2001, 2002, 2003, 2004, 2005, 2006, 2007.
CHASSIS  W203 W209 W211 W219 R230 W251


  •  Manufacturer Part Number: 0 00 90 56201,0 06 15 32928,0 04 15 36628
  • Interchange Part Number: 006 153 29 28,0061532928,004 153 66 28,0041536628 802 33077 001 0061532928


Besides needing a  Mechanic Tool Set and screwdrivers  you will also need a set of Female E Torx tools to remove the bolts that hold the sensor in place female Torx E set.mercedes oil level sensor B40 bolt removal


  1. Raise the car on the front. The easiest way to do this is to use ramps like the  RhinoRamps Vehicle Ramps (Pair, 12,000lb. GVW Capacity) Make sure to secure the car with jack stands.
  2. Remove the lower paneling. Get under the car and remove the lower engine compartment paneling. You will have 6 to 8 plastic fastener which you can remove with a screwdriver or a 8 mm socket.
  3. Remove engine oil. Remove the oil drain plug and let the oil drain. You will need to do this or the oil will get all over the place when you remove the engine oil sensor latter.
  4. Locate the oil level sensor (B40 Oil Level, Engine Oil Tempearture and Quality Sensor) which is shown in the picture below. mercedes oil level sensor sender unit
  5. Unplug the connector to the B40 Oil Level Sensor. You will have to press the small tab on the connector and pull it out.mercedes oil level sensor sender unit7
  6. Remove the bolts that hold the sensor in place using E-10 socket.mercedes oil level sensor sender unit6
  7. Pull the oil level sensor down carefully. There may be some oil that will come out when you remove the oil level sensor B40.mercedes oil level sensor sender b40 temperature oil sensor
  8. Install the new sensor by pushing it in the place of the old one and installing the three screwes that you removed earlier.
  9. Tighten the three scewes preferably using a torque wrench like the torque wrench. The bolts need to be tightened to 10Nm if they have pre tapped thread or 15 Nm for non tapped thread.
  10. Don’t forget to add OIL to your engine. That’s it, you are done!
  11. Please come back and use the comments section below to help others with your recommendations and what you did differently.

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