MB Medic Mercedes-Benz Repair Guides, Service, How To DIY
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In this guide (5 sections)
Below, you will find step-by-step instructions with pictures on removing and installing a new engine oil sensor on a Mercedes-Benz engine. Part numbers related to the oil level sensor are shown below; there could be more. The oil level sensor (B40) measures the oil level, the oil temperature, and the oil quality. This E320 showed a “Reduce oil level” warning in the 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 to which these instructions apply:
Applicable Models
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
Required Parts
- 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
Required Tools
Besides needing a Mechanic Tool Set and screwdrivers, you will also need a set of Female E Torx tools to remove the three bolts that hold the sensor in place: a female Torx E set.
Step by Step Instructions
- Raise the front of the car on level, stable ground, and chock the rear wheels, because those are the wheels still carrying the car. The easiest way up is a pair of Vehicle Ramps (Pair, 12,000lb. GVW Capacity). Drive up slowly, set the parking brake, and check the car is settled before you get under it. If you use a jack instead of ramps, the car must come to rest on appropriately rated jack stands at the lifting points Mercedes-Benz designates for your model. Never work under a car held up by the jack alone.
- Remove the lower paneling. Get under the car and remove the lower engine compartment paneling. You will have 6 to 8 plastic fasteners, which you can remove with a screwdriver or an 8 mm socket.
- Remove engine oil. Remove the oil drain plug and let the oil drain into a pan. You must do this, or the oil will get all over the place when you remove the engine oil sensor later. If the engine has been running, the oil is hot enough to scald, so either let it cool or wear gloves and keep your forearm clear of the stream.
- Locate the oil level sensor (B40 Oil Level, Engine Oil Temperature, and Quality Sensor) shown in the picture below.
- Unplug the connector to the B40 Oil Level Sensor. You must press the small tab on the connector and pull it out.
- Remove the bolts that hold the sensor in place using an E-10 socket.
- Pull the oil level sensor down carefully. There may be some oil that will come out when you remove the oil level sensor B40.
- Install the new sensor in place of the old one and refit the three bolts you removed earlier.
- Tighten the three bolts, preferably using a torque wrench. The bolts need to be tightened to 10 Nm if they have a pre-tapped thread or 15 Nm for a non-tapped thread.
- Refit the oil drain plug before you add any oil. The procedure above took it out and nothing has put it back. Tighten it to the figure for your engine, fitting a new sealing washer if yours uses one, then refill with the grade and quantity your engine calls for. Run the engine, shut it off, let it stand, and check the level: that reading is exactly what the sensor you just fitted will be reporting, so it is worth getting right. Here are two ways to check the oil level properly. Draining and refilling also resets the clock on your service interval, so you may want to reset the service reminder while you are at it. That’s it, you are done!
- Please come back and use the comments section below to help others with your recommendations and what you did differently.
Related Reading
What Scanner Can I Use to Troubleshoot Mercedes-Benz Engine Problems?
Before replacing the oil level sensor, scan the engine control module and check the B40 oil level and temperature data. The YOUCANIC UCAN-II Pro can read full system fault codes and live data and includes full AI Diagnosis, built-in TPMS sensor programming, a rear VIN scanning camera, coverage for 140+ makes, 3,500+ active tests, 1,000+ special functions, no subscription, and no AutoAuth required.
Before you buy parts, scan every control module, not just the engine. It shows the root fault behind the warning lights and tells you whether the problem is still active. See how to do a full health check.
