I recently bought a 2019 E Class wagon and have been reading the Owner's Manual. In the car wash section, it says that the smart key must be 10 feet from the vehicle,otherwise the tailgate may open accidentally. Two paragraphs further on, it states that the smart key must be in the car, otherwise park will be engaged. I tried to open the tailgate using the hands-free access feature with the smart key in the console, and it didn't open, so I think its safe to use the car wash, but I'm still a little worried. Does anyone have personal experience with taking a wagon through an automatic car wash? (The kind where you drive onto a conveyor, and the car is pulled through while you remain in the car.)

 

I take my W166 with comfort access through a car wash as you describe it.

I don’t see the concern. What exactly are you concerned about, and how would the concern present itself?

 

I leave my key in the car with the engine running. I open the trunk so that it can be vacuumed. After the car comes through the wash the attendant drives the car so that the interior and windows can be cleaned. While in the wash the car is in neutral.

I have a 2019 E450.

Hope this helps

 

I'm concerned because the owner's manual specifically states: "To avoid damage to your vehicle when using a car wash, ensure the following before hand: The smartkey is at a minimum of 10 feet away from the vehicle, otherwise the tailgate could open unintentionally.

 

One can always deactivate that feature by turning off Keyless Go.

 

Oh! Great! Somehow that got past me. Thank you!

 

I've never had the hatch try to open when going through the car wash.

 

That's good to know. Thank you.

 

The owner's manual is perhaps not quite clear on this and it's not specific to the wagon, either. The note on the key fob needing to be 10ft away is if you are washing the car from the outside with the key in your pocket. Otherwise while you are standing behind it and washing and accidentally swipe your foot under the bumper the hatch could open. Similarly you will experience the car constantly locking and unlocking as you spray water onto the door handles. The hatch/trunk comfort access only works if you are standing being the car with the key in your pocket. Nobody can open the trunk with the foot motion if the key is inside or to the side of the car. It only works in specific locations. For automatic car washes where you remain inside of the car with the key, there is absolutely no concern.

I alternate between hand washing my cars in my driveway and taking them through a touchless automatic car wash (car remains stationary, but doesn't matter). When I hand wash it in my driveway I keep the key inside the garage and all is fine. I sometimes also stop at one of those self-service pressure washer stations. In those instances I leave the key inside while I spray down the car to avoid the constant locking unlocking etc. It's all fine. Car won't lock with the key inside, so there is no risk of getting locked out.

EDIT: BTW, some other cool features of the MB key fob. If you press lock twice, it deactivates the keyless function. So that's another option if you are washing your car. It basically puts the key fob to sleep until you press the unlock button again. They key also has a motion sensor in it. If it doesn't sense any motion for about 2 minutes it will also go to sleep and stop sending out a signal. This is to mitigate the recent spike in car thefts, where thieves use a device to relay the signal from your key fob left inside of your house to the car and then drive off with it.

 

Thank you for your very complete and comprehensive answer. It makes a lot of sense to me, as I could not understand how MB could have permitted a situation that could possibly lead to damage in an automatic car wash. I wash my cars by hand during the warmer months, but I live in Maine, and during the winter the wise owner has his car washed regularly.

 

"you will experience the car constantly locking and unlocking as you spray water onto the door handles" I've experienced this before. It's quite annoying. I didn't know I could deactivate keyless go by pressing the key fob twice.

 

That's a good point. Thank you.

 

Ah, but the most remarkable thing about the MB key fob is that it is $925 USD programmed.

 

Geez - Don't lose it, huh?

 

Now you tell me.

 

I've had the same problem - very annoying. The downside to double pressing the key fob twice is that the car locks, and the mirrors fold, so you can't clean the glass. I suppose you could go into command and deactivate this before washing the car, but its another silly step to have to take.

Is there anyway of deactivating keyless entry while leaving the car unlocked?

 

Well, if you can't keep the fob far enough away, then just put it inside the car while washing. Problem solved. If you really wanna keep it outside, I suppose you can do the double lock and then unlock the car with the phone app, but just leaving the key inside the car is much quicker and easier.

 

Beware of leaving the fob in the car. The car can lock with a fob inside. My wife inadvertently locked the car while digging in her purse for a house key as she was picked up by a shopping companion. I was stuck until she returned.

 

Folks, unlock the car, throw the fob in the front seat, close the door, and wash the car.

 

It is possible to lock the car with the fob inside if the battery is dead or something blocks the signal. Also, it appears to be possible if the car is locked and then you open a rear door while you are in possession of the fob. The car will temporarily unlock and let you open the rear door. If you then put the key inside and close the rear door again, but never open one of the front doors within 30 seconds or so, the car automatically re-locks even with the fob inside. This is a safety feature for if you accidentally unlock the car with the fob in your pocket, but never actually open the front doors. It seems to be an oversight by Mercedes that opening a rear door doesn't count in this scenario and you can end up locking your fob inside. However, if the car is unlocked and one of the front doors has been opened recently, which is normally the case and you put your fob inside, then the car won't lock even if you try. If your trunk is open, and you lock the doors from the outside, then put the key in the trunk and close the trunk, it will automatically pop back open after a second. If it does ever happen, use the phone app to unlock the car. If you have a wife that has this habit and she even locks her phone inside the car, make sure that both of you have the app and are setup as users so one or the other can unlock the car remotely. I believe you can even call Mercedes and they can unlock the car remotely.

 

Thanks for this tip. It had not occurred to me