Check the oil with the dipstick and if it's not leaking...ignore it. The lower oil pan has to come off and I seem to recall that isn't much fun on the 4Matic.

The sensor is on the right side of the engine down at the crankcase, you'll see the wire. I'm not sure about that circuit, but you can try unplugging it, maybe that will turn out the malfunction.

Good luck.

 

You may think my answer is strange but it happened to me,

Make sure your battery is fully charged, if it's more than 4 years old, it maybe weakened even though your car starts fine. Since the battery is such an integral part of the system, it triggered the "oil level sensor" warning.

Take you battery for a test, I replaced mine and the sensor warning went away.

 

Assuming that you have engine M112, the sensor will be B40, which measures level, temperature, and quality.

As you have recently changed the oil, I doubt if any of the above are bad, and probably the sensor is toast. As stated above, you must drain the sump and remove the lower pan to access this sensor. Not difficult, but the pan must be re-sealed (in a specified manner) using a special silicone product.

Provided that you catch the oil in a clean container, it can go back into the engine. I realize that you can check the level with a dipstick and ignore the warning, but this is going to come on every time you use the car, so it will become tiresome eventually.

 

Thanks to all for replies to my question.

 

Location of Sensor on 1999 E320

The message "Oil Sensor Defective" is displayed on about half of my trips with my 1999 E320. However the sensor measures the oil level without fail.

Today I removed the plastic cover and located my Oil Level Sensor. See attached picture.

Above the oil pan on the passenger side the device stands with the electrical plug at the top. I unplugged the cable and found that a few drops of oil had leaked into the connector but not enough to see leakage onto the device. I thoroughly cleaned the inside of the connector and plug with CRC QD Electronic Cleaner. It is obvious that the device must be removed by removing the oil pan. Also I am guessing that the computer detected the oil in the electrical plug and hence turned on the "defective" indicator.

I started the engine with the connector unplugged to see if the message recurred. It did not. In fact, I then turned on the ignition and waited for the "Display Oil Level" message. I pressed the 'O' button twice and the car did not respond.

After plugging in the electrical plug and repeating the procedure, the car responded with "Oil Level Ok".

I do not plan to replace the sensor unless the "defective" message occurs more frequently. Intead, I will have my oil changed since it it currently due. I will edit this report later if anything develops.

The part number of my sensor is 001 542 72 18. Also printed on the device is
Temic 139 5101.

Hope this helps someone.

 

The message "Oil Sensor Defective" is displayed on about half of my trips with my 1999 E320. However the sensor measures the oil level without fail.



I started the engine with the connector unplugged to see if the message recurred. It did not. In fact, I then turned on the ignition and waited for the "Display Oil Level" message. I pressed the 'O' button twice and the car did not respond.

After plugging in the electrical plug and repeating the procedure, the car responded with "Oil Level Ok".

Hope this helps someone.

I went by the above quote, guessing that if the wire to the sensor is to be disconnected, then I won't get the defective sensor message ... maybe that is not the case...

 

Well guys I had my Oil changed at the dealership about a week ago I'm going to check the plug and see if the is any oil om or around the plug. Keep you posted thank you

 

There looks like an oil leak in the area of my oil level sensor on E320 gas engine.
I do have the fault in red on display.
To fix the leak the sensor needs replacement or is it a seal?
And this can only be done by dropping the oil pan?
Does it unbolt from inside?
Anyone have details of how it it removed?
Thanks

 

If i take the sensor out, will the display light showing defective sensor go away ?
thanks.

 

Loosing connection by disconnecting the sensor can only guarantee the notification will be left on.

 

as sensor of engine oil measure quality , temperatuer and level of oil in engine can warning ,,engine oil sensor'' be reason of not proper engine use ?

 

UUUHHHH, What??

 

Probably uses google translate.

See location.

Also, necropost. I do love me some necropost.

 

His profile says "Georgia". I don't think it's Ray Charles' Georgia but probably the former Soviet republic. Not a bad effort considering. You got to give the guy credit for trying...

Fred