check engine oil at next refueling
This has happened to our 2015 GL550 for two years now, roughly six months after the annual service ... and both times while driving on hilly roads! Our MB service advisor guessed the hilly roads part as soon as I described the error message and the solution is obvious, simple and free ... bring it in for an oil top up and a free car wash!
We can speculate that driving on hilly roads 'sloshes' the oil and eventually too much oil stays in the cylinder heads rather than the sump, but at most the oil level is less than a quart low after it all drains back so it's a nuisance, but not a problem.
As long as you don't shut down before you get to the dealership the error message will stay displayed. If you have to shut down take a picture with your 'phone to show them.




