I just replaced the oil level sensor on my 2010 W212 (E550) 2WD, 140k miles, it's a straightforward job of removing the lower oil pan and three more screws to remove the sensor and its bulkhead (with integral connector), that passes through the casting between the oil sump and exterior of the engine. The frustrating part was removing the plug from the old connector, I could see connector on the engine harness had a light gray locking piece and looking at the new part could see some barbs on the connector body but that was about it, The car was on ramps and there wasn't much space, furthermore I've only one elbow per arm so couldn't get much leverage on the connector. In the end the gray piece came out and I could pry the connector over the barb, the gray piece never went back on, the barb still worked on the new piece.

Is it just me who has to fight these things? Are there some techniques others have developed? Was the gray piece designed to be removed? Are the connectors color coded (gray tabs go in, red up, ???). Do the pro's have some tools that help with these? Am I just venting? At least Toyota sells the component parts of connectors, the plastic is as fragile as it is on MB but as long as the socket/pin is still properly attached to the wire you can rebuild the connector.

Thanks in advance for any suggestions.

Peter

 

Can u take a good photo of the connector ?

If it is a Hirschmann , I can show you tips and trick for stuck or never-opened/removed-ever connector.
I never gone that far to oil level sensor. Is this the one ? : https://www.ebay.com/itm/203688820171 << The female side is not good enough to know the male connector side.



This is a Hirschamn. Many other brand also has that grey locking feature, example KOSTAL, but tthe tips and trick is not the same.

 

Here's the link to the sensor, it's used in a number of cars, . The car is back together now but I took some photo's, what I didn't realize is that the piece broke (thought it just fell out), attached are pictures of the barbs on the sensor, the connector mated to the sensor and the broken part of the gray piece. I can also see looking at the gray piece that it was very dirty - maybe cleaning it would have made it operate properly. Unfortunately I can't get close enough to see if there are logo's on the parts - the middle photo in the second row looks very similar. Thanks for any insight. Peter

 

The grey (sometime nylon off-white color ) tab is an extra lock only. See below.
In vibrating devices, MB uses this extra lock. It is an option from Hirschmamn.



In the in-fuel tank fuel filter pressure sensor and fuel level, there is no vibration. The connector has no Extra Lock




The real or primary locking mechanism is the BLACK LATCH ( my term for it
The See-Saw method for lifting up Black Latch square hole and free itself from the female sensor small tab
















Now, how to un-plug this connector ?

01. If it is dirty, best to air-blast them clean. If dirt does not allow Black Latch to lift up, you can not remove this connector.

02. Pay attention well here. When one has dis-engaged the Extra Lock and wants to remove the connector.... Make it a habit to push-in the connector FIRST into the female side...yes like plugging-in the connector.
Doing that push-in, will ease the Black Latch square hole from the female connector Tab engagement.
It is by our nature and habit, while pressing down the Extra Lock to get Black Latch to be squeezed down, often we are not aware we are also doing pull-out. This is that stuck connector feeling when Black Latch is still biting the Tab.
Squeeze down the Extra Lock/Black Latch a few times to get it un-sticked, just in case some dirt still there.

03. When a connector has not been removed in years, the silicone seal on the male connector does a very good job at making that STUCK feeling.

04. If space and fingers/hands allow, always help the connector removal by using other finger to push it out at connector front side, while doing the squeeze of Extra Lock and pulling out the connector from the rear.
This method helps a great deal.



A final view of the Extra Lock if seen from the bottom.




Your need to get that broken part of Extra Lock if you want to undo the connector next time.



This connector is called SealStar 2 pole, made by Hirsmamn and is used in the engine bay like 70% of total connectors.... this SealStar family has 2 , 3, 4 and 6 poles ones.
Google my post on connectors... me too is spending time learning about them and keeping spare for my itchy fingers sake.

OK, drive safe

 

It is easy to replace new male connector of yours. No need special tools. U need to show me the KEY* or Groove position in respect to its round or flat edge ( OE call it coding ) so you can buy from a 3rd party .
There are 3 to 4 variants. You are using 2 pole type connector, but the sensor only has 1 pin, still the female side at the sensor is a 2 pole version.
Sometime MB does special order and its Locking Mechanism is opposite side on purpose compared to OE catalog.

 

Excellent information here. Thank you!
these connectors are always difficult

 

Very much appreciate the info provided, the car is back together (and there's no more false check oil level messages) so I'll leave well alone, once again thank you for the detailed replies.

Peter