Armanidog

drwolf

Gotta take it back to the dealer if you ask me, very strange on a new car

GeneralToner

Not sure if you have the offroad package or not. I have the offroad package and while driving my wife accidentally (and without realizing) hit the manual button while putting her drink back in the cup holder. I couldn't figure-out why the 550 went into manual but couldn't easily figure-out how to get back into auto while driving down highway.

Just a thought, not likely since you had dealer look at it but just a thought from experience.

drwolf

the way you solve is you shift to N, then back to D, then it'll go back to auto unless you use the gear shifters then it'll turn into M mode

c4004matic

I was wondering the same thing. If this is not the problem, there is a definite problem with the tranny.

JoeMa

Other manufactures provide a simple way to go from Manual back to Auto by holding either paddle shifter for a few seconds. I've never understood why MB didn't employ the same method. Maybe some models already do this but not the GLS.

c4004matic

It does just hold the right paddle for a few seconds. However since the the GLS has a munual mode button for off roading I have never tested it on the GLS.

JoeMa

H3NRYR

Same here, it will randomly switch to and will not go back into auto till I pull over and turn off the car.

The dealer has done a software update I will keep you posted

Daniel Haydt

Many update? My 2017 450 GLS just started doing the same thing and the dealer thinks I’m crazy

Jt0230

So this happened to me on my 2017 GLS 550 when I first got it. The problem was my puppy pushing the manual button by the cup holders when she was moving around. To go back to automatic all I did was to push the button again and it went back to automatic. Hope this helps. If the dealer hasn't fixed the issue I would keep returning to them till its fixed.

mintberrie

I have a 2018 GLE 400 that is also experiencing the same issue intermittently for over a year now. I used to own a 2015 GLE and never experience this issue.

When driving this vehicle on small roads the vehicle will automatically shift to m1 mode without any user initiation. The paddle shifts were never touched.
It happens intermittently from over a few weeks to a few months and every time I have brought it into the dealership - they run diagnostics and test drive and, surprise they cannot find anything *rolls eyes*

I am at my wits end. I've asked for computer reports on the vehicle to confirm all the instances the vehicle has gone to m1 mode from automatic and to avail.
Thankfully the vehicle has never engaged to manual mode while on the highway yet as the only way to disengage this issue is by pulling to the side and turning off the vehicle and turning it back on.
This has happened at least 5 times over the last year - and no help from the dealership.

Does anyone here have any input or resolution ideas?

T.Hunter

I know this thread is old but Im having the same issue. My gle 350 keeps shifting on its own while driving from automatic to manual. I have to pull over and turn it off to get it to go back into automatic

chassis

Replace main battery
Replace aux battery

If problem still present scan using XENTRY and focus on the transmission shift module/servo.

sindlefinger

same happened to me, after I read these posts I went an a test drive and when i pushed the manual button it went back to drive.

Jt0230

Any updates?

Beemie

I am having this same problem on my 2018 GLS 550. It started about two weeks ago, where I would look down and see that I was in manual with no input from the paddle shifters and nothing touching the "M" button in the center console. It happens consistently every drive, though it may not be in the first 15 minutes. On a few occasions, it has been problematic in that I'm pulling out of a stoplight and it will not shift up from M2, either by the + paddle or otherwise (even holding the + paddle). Eventually it rights itself but sometimes it's close to redlining. Other instances, I have gone to pass on the freeway and found myself in M9 with no power when I step on the gas, and no response when I try to switch back to D. I took it to the dealer who found a problem with the + paddle but otherwise can't duplicate the problem of course. (I've shared video with them that I took while driving). They also say that the paddle shifter problem is not covered under the CPO warranty, which I find outrageous if the paddle shifter is effectively an electrical switch communicating with the transmission, and the electrical system is generally covered. I'd love to hear if others have successfully resolved this issue or gotten paddle shifters covered by warranty.

chassis

What was the "problem" found by the dealer regarding the paddle? The paddles are parts bin commodities used across many MB models and years.

Replace the main battery and aux batteries. A 4 model year old car can have batteries as old as 5 years depending on when the car was built. 5 years is the start of the replacement window. These cars have a heavy electrical draw from all of the gadgetry, and MB skimps wherever they can, for example on batteries.

Replace the main and aux batteries and report back.

Promo Bob

strar
start t/stop the car. Sometimes got a fluke like that.

brian.grace

I have the same vehicle and have had this happen a few times. Ultimately it resets when I shut it down and restart. PITA, but only has happened a handful of times over my three years with the vehicle.