Anyone else have this problem? When I pull into a parking spot, shift the vehicle into park, ignition still on, the car will slowy creep backwards or forwards depending on the slope. You can hear the brake creep. Once you turn ignition off, this stops.

Seems like when you shift to park with ignition on it's using the brakes to hold the vehicle and transmission is shifting to neutral. Then when you turn the ignition off, transmission goes to park and brakes release and car roles a bit until parking paw engages. Just a theory. Taking it into the dealer Monday for this issue and curious if others have experience. I searched for a TSB on this and did not find anything.

 

I'm assuming your foot is on the brakes when you shift the vehicle to park, correct? If you then take the foot off the brakes, it's normal for the vehicle to move a bit if the ground isn't level, as there is some play in the transmission. Once you turn off the engine, the parking brake should engage and hold the vehicle. So the proper procedure is actually to shift the vehicle to P, keep your foot on the brakes, turn off the engine and wait for the parking brake to fully engage, then take your foot off the brakes. This ensures that the weight of the vehicle is not hanging on the parking pawl and potentially damage it. If you find your transmission has a lot of play in P, then you may have already damaged the parking pawl.

 

Yes foot is on the brake and vehicle is at standstill when shifting into Park. I should clarify the slope I'm talking about is essential level ground. I'm pretty sure the parking pawl is not engaged until the ignition is turned off and electronic park brake is automatically applied. When Ignition is turned off, that is when I experience the normal vehicle movement just like any other vehicle until parking pawl is engaged. What I experience in Park with Ignition on is brake creep, brake moan, whatever you want to call it. Every ~1 - 30s the vehicle creeps ever so slightly then stops (you can hear the brake creep noise when it does this), then this cycle keeps repeating until ignition is turned off.

 

-IF- it is the same as my car (the E63S). If I stop the car and turn off the engine, the car will roll (out of the garage for instance) if I take my foot off of the brake. Only when I put the car in P or open a door (putting the car into P) will the car not roll if I am on an incline. The GLS and the other E do not do this.

Many times I have been on the phone, stop, shut down the car and will be talking...rolling out of the garage....

 

I don't know about you guys but when I first learned to drive, I was told to put my foot on the brake, put car in Park, and then release the brake! This works for any brand of car and anything outside of this order is asking for trouble!

 

This sounds like your parking pawl is malfunctioning. It most certainly engages the moment the car is put in P. As said it might roll a little bit due to the slack in the transmission, but then the parking pawl will hold the vehicle. You don't have to turn off the engine first.

 

This is what the parking break is for ... to take that pressure off the parking pawl and transmission.

 

I guess I'm on the opposite end. I ever only using the parking brake when on an incline or if I think the car is going to roll away.

I hardly ever engage the parking brake "on purpose"! Why do I do this? Not every car is like a Mercedes where the parking brake engages when opening the door/turning ignition off.
There are still cars on the road that behave the way they "used to"!

Sound like OP's parking brake is shot. I'd definitely get that checked out!

 

Electronic park brake is working good, my symptoms are before this is applied. Wondering if when shifting to park it uses Auto Hold function to hold the vehicle and not enough pressure in the system so you get a little brake groan. I'm fairly certain parking pawl does not engage until ignition is turned off. I'd like to get a CAN log, that will explain this in a jiffy.

 

"Hold" is only on demand for Mercedes. You have to press the brake once and then firmly a second time to activate.
For all intents and purposes, "Hold" never activates automatically!

 

Well, there are also cars with manual transmissions which don't have a parking pawl. I've driven manual transmissions for over 25 years, so securing a vehicle with the parking/handbrake is second nature. I learned driving with a manual transmission and my current car is only the second car I own myself with an automated transmission. Ironically, though, I just realized that the automatic parking brakes have made me complacent. Just got back from a trip to Europe where I usual rent a car with a manual transmission. The car this time didn't automatically engage the parking brake and after a few days I realized that I had left the car parked w/o applying the parking brake manually. Luckily it was on level ground and it didn't start rolling away.

Correct, and if HOLD is active, it deactivates the moment the transmission is put in P. One more time, if the parking pawl doesn't engage when the transmission is put in P, then something is wrong with the transmission.

 

Yep, sounds broken.

 

Will be curious what code is stored, might just be a software issue instead of a mechanical one, this is on the X167 GLS? If so it might be too new for transmission failure (unless it is defective from factory), might just be a glitchy software.

 

I pulled all the codes a couple days ago as I have an appointment with the dealer tomorrow for this and a 48v issue. No codes related to the brake creep issue. I'm certain it is not a mechanical issue with the transmission, or parking pawl. Found a thread in the GLE group with others reporting the same experience of brake creep noise while in park on level ground with ignition still on but no resolution. I guess I will see what happens tomorrow at the dealer....hoping to show them in the parking lot.

https://mbworld.org/forums/gle-class...-parked-2.html

 

That almost sounded like a parking brake engaging after inactivity (like idling in park).

 

I notice the same on our 2020 GLS580, mostly when parking on an incline. It will creep very slightly, you can hear the brake pads/rotors slipping a tiny bit, often creeping more than once if sitting for a while.

Looking forward to what you find out.

 

That would be disconcerting if the brakes are not properly holding the vehicle on an incline. Is this while your foot is on the brakes or with the parking brake engaged? The former should just be a matter of pressing harder on the pedal, but the latter needs adjustment. The parking brake is supposed to be self calibrating, but if the clamping forces are not sufficiently dimensioned then this would be an issue.

 

For me, its when the vehicle is in park, foot off the break. Oddly, it doesn't happen immediately.

 

I noticed something like this the other day. Pulled out of the garage and wanted to go grab something I forgot. I hit the park button and then shutdown. On shutdown the vehicle rolled forward a bit until the parking pawl caught it. Later that day I had the vehicle info up and could see brake application percent. I noticed that the brake % I used to hold the vehicle before shifting to park was being held so long as the engine was running. I only noticed it recently so I haven't fully investigated if it does this all the time or just sometimes. I had not given the brake pedal an extra push to engage HOLD.

I wonder if this is happening to the others who report movement when they don't expect it.

 

Any update from your service appointment?

 

No word yet from the dealer. They have had the car since Monday and are still looking at it. I will post what I learn once I get the car back.

 

Dealer had the vehicle for 4 days last week and as expected it was not a great use of time. They fixed 1 of 5 things I brought it in for. For this specific issue they claim they could not reproduce it after 4 days. I reproduced in their parking lot before I left with ease. I'm pretty frustrated with the service departments these days and lack of troubleshooting abilities. Had I had more time I would have requested the tech to come with me but had to run to get kids from school. Hopefully someone else is able to get some better answers.

 

Always request a test drive with the foreman when dropping off the car and demonstrate the issue for something that might be difficult to reproduce. It's easy for you to reproduce, because you've been living with the issue, but trying to explain it to somebody else and for them to reproduce it isn't always easy.

 

I totally agree.
I'll go further and say it's incumbent on the owner to be able to demonstrate an issue, if it's difficult to replicate. It might mean finding a place near the shop where you can take a tech or the Service Manager, so they can reliably replicate your problem. And the technician can check his work to make sure he's fixed your problem.

It's just as frustrating to a technician not to be able to replicate a problem, as it is for you. They have an additional problem because the service advisor is an intermediary.

I also give a written summary to the service advisor beforehand, and pay close attention to the specific wording when he writes it on the work order. (Mine's a He)
Give we need to give as much information as possible to the technician.