Hello all hopefully someone can help, my park button wants to respond half the time sometimes even less than that causing me to open the driver door so it overrides it and goes into park. A few times i have pressed the parking button more than once seeing if it was jammed and the check engine light showed up. Left the car sitting over night wanting to take it to Mercedes in the morning and it went away but the issue still remains. Maybe a silly question but i have a tune on the car could that have anything to do with it? Regardless the car runs and shifts great. Thanks

Hook up a diagnostics tool and see if there are any error codes. One question, when P doesn't work, is there a small arrow next to P in the instrument cluster pointing at the letter P? The small arrow indicates when the transmission can be put in Park. Usually disappears above 5 mph. If the arrow doesn't show when you are stationary, then it's likely a sensor or something that doesn't recognize it is safe to put the transmission in Park.

I have not paid attention to that but thanks i will try that and get back to you on that.

Yeah it shows up but still not shifting into park sometimes and the check engine light turned on again.

Next step is reading out the error codes to see why the CEL is on. Sounds like there's an underlying issue. If you don't have a code reader, stop by an Autozone or similar. They can read the codes.

Yeah so i just went to get the codes scanned and it shows no codes…

Time to take it to a dealership or an independent Mercedes shop with the right tools. There's the possibility that the codes are manufacturer specific codes, which depending on what scanner was used may not come up.