Basically when you are in 3rd gear and accelerate (for example an on ramp) and the car drops to second the down shift is brutal, like as it shifts off of 3 the car has about a 1 second hiccup between 3 and 2, its a VERY slow downshift unlike every other shift in the car, and you end up popping forward before being thrown back in the seat, like the transmission is slipping, or if you were a stick driver and downshifted hard without rev matching. It was always a little stiff but never like this, its really bad.

Car only has 25k miles and is still under warranty for 3 more years so I'm not totally concerned, just want to see if anyone else has seen this issue before I bring it into the dealer for service, as I feel like they are going to tell me "that is normal operation" or nail me for a transmission service that a car with only 25k miles that is driven very gently should never ever need.

 

Well dealer says they updated the transmission software and did a re-adaptation that fixed it. I pick up tomorrow morning so we will see.

 

I have a 2013 E350 4matic with the sport package, and still under the extended Mercedes warranty. Mine does this same exact thing, however it does it when dropping down to 4th gear. I've noticed that this only happens when I need to accelerate hard. A few times, this happened in conjunction right before "limp home mode" being activated. It once occurred on a trip as I got on the freeway from a rest stop with congested freeway entrance that also had a short onramp. If I'm on the freeway, cruising at 60-65, and accelerate slowly, the issue does not occur. It only occurs when I accelerate hard, like situations where a freeway onramp is super short. Feels as if something is slipping, finally engages when the torque is really high, and after the SUPER aggressive jolt/bang/hit by a 5,000lb hammer, it then accelerates. After experiencing it many times, and purposely trying to create the issue, it seems that the signal to shift down is sent to the transmission, the shift occurs, but torque converter slips due to a lag caused possibly by clogged valve, and due to this lag, it engages at higher internal pressure levels and engine rpms. I've taken it in for this issue 4 times to my Mercedes dealer, and have never been able to fix it. They've reprogrammed the transmission, replaced the fluid, replaced gas pedal, replace throttle wiring, and a few more things I can't remember. It's only until lately that I've researched issues with the 7G transmission related to clogged valve filters that might cause this issue. I just don't really have time to keep taking it in, or playing with it.

 

Thanks for the reply, thats exactly what I was feeling but less often and never seeing that "limp home mode". I drove it home today and it did seem smoother on downshifts but still not really as smooth as I expected, or as smooth as my wife's GLE 350 which is essentially the same drivetrain. I did see what you are describing about the valve as well and I assumed thats what they were gonna do. I guess I know what i have to look forward to now.... I knew this wasn't going to truly fix it.

 

Longshot here, but I had the same problem in mine and it went away after new intake manifold and engine/transmission mounts. I think the main culprit was a broken lever on the intake manifold, because the transmission was expecting the car to produce a certain amount of power which was thrown off because the intake flaps were in the wrong position, and the torque value to the transmission was not what was expected. Scan for an 0520 code.

Again, this is a longshot, but worked for me.

 

I don't see any movement in the engine bay, and the car only has 25k miles, I can't imagine engine/trans mounts failing that quickly. The programming seems to have fixed it for now, but I anticipate that will change once I've driven it more when it cold.

 

Your car is 5 years old and that's more than enough for engine mounts to fail on these cars. Others can chime in if they agree or disagree on that.

 

Not saying you are wrong, but if true thats really annoying that a part like that would fail so quickly.

However I would assume I would notice more vibration issues and it would be more consistent since a part is physically broken, mine is very inconsistent, and like i said seems to be cured so far leaning me towards it actually being a computer issue, or being one of the many known issue with these 7 speed transmissions and valve body or blockage issues.

Either way I have 3 more years of warranty left so as far as I'm concerned the transmission could fall out of it. But the loaner C300 sucks (that car really sucks, a tin can with a fake veneer), so I'd much prefer to be in my car.

 

Hello sir .. I’m happy that i meet someone have the same problem of my car .

 

A 2018 E350e is not the same at all as a 2014 E350.

 

Haven't been on here in a couple years, but man do I miss my E350. I ended up getting rid of this car after dealer not being able/willing to continue attempting to fix issue. The issue seemed related the shift solenoid assemblies. They attempted to "flush" and then replaced the solenoid filter assemblies, but the issue still persisted. To continue further investigations would involve replacing the transmission controller, solenoids assemblies, and many more parts that were not were only available via shipping from Germany, and the dealer was not willing to order another part and have it not work. On top of this, Mercedes corporate from Germany suggested a possible solution to resolve the issue would be to swap the transmission, but the dealer claimed if the issue was not resolved, the parts cost would not get covered under warranty. I know they were being a pain in the a$$ and just didn't want to deal with my car, but that was my last straw. I traded the car in at another dealer. In short, my original Mercedes dealer was not willing to risk further warranty costs, and other dealers would not want to work on it due to previous attempts from another Mercedes dealer having failed. I do miss it so much though!

 

Was hoping you also tried another dealership and see if they are willing to help, I don't know about your country but in the USA they are all privately owned by dealership groups so they operate somewhat differently.

 

Sorry to hear about it , you can always find another E350 . I know how it feels , I had sold my W212 for arbitrary reasons However. I couldn't resist and picked up another one afterwards .

 

Sounds very much like my issue...

https://mbworld.org/forums/e-class-w...-car-jerk.html

 

Wait unless I am missing something (read it wrong or didn't notice it mentioned) but can't believe OP of this thread's dealership didn't at least change the ATF?

 

currently having this exact issue, Flushing the ATF fluid seems to have actually made it worse, but it also got really cold at the same time so the cold weather maybe the cause of it getting worse. At first i thought we under filled the ATF when we flushed it, then i read about this symptom being caused by a bunch of other things as well. Upshifts are all perfect, but when pressing the gas pedal 75% or more, when already going 30-40mph or more, there is a huge delay in the transmission downshifting to 2nd or 3rd gear, and its extremely rough, exactly like OP described. Car is a 2013 E350 4matic sedan w/ 86k miles. When flushing the ATF, it took 5 full quarts, before beginning to flow out after we started the car on the lift, warmed up the fluid, and went through PRND several times while foot was on the brake. If anyone else has done this flush, and 5 quarts seems too low, please let me know. We made a mistake by not measuring how much fluid came out, so it might be under-filled, lesson learned. I used the Elring 620.160 kit (which seemed excellent) and Fuchs(Pentosin) 7134FE fluid, which im pretty sure is the factory fill ATF fluid.

When i first started noticing this problem, I reset the shift adaptations, but that only helped a little bit and was temporary before the rough downshifts returned. Then i flushed the ATF, without resetting the adaptations so i could see if the fluid alone would help, it didnt help, so I then reset the adaptations again which once again only helped a little bit, temporarily, before the problem returned again and this time it became even worse.

A friend who works on mercedes told me to start by replacing the AUX battery, and if that doesnt help, i need to have it scanned with Xentry to see if i need a TCU software update like OP stated. Its been driving me crazy, and its so rough im worried its hurting the transmission.

I did also have accelerator pedal codes which caused the car to go in limp mode whenever i would floor the gas pedal, but i cleaned the battery grounds, and removed the gas pedal, cleaned the sensor connection to the gas pedal, and that problem has never returned. Seems like they are related but not sure, so wanted to mention that.

 

You've established a really good connection between the accelerator Limp-Mode and the tranny not reacting well to it.
It has learned not to shift right.
I'm not sure what exactly to reset or retrain in this case.

 

But wouldnt an issue with the accelerator pedal just cause it to shift at weird times, or hold a gear too long if its not getting correct signals from the pedal sensor? Why would an issue with the pedal cause the transmission to shift rough, and specifically rough on downshifts only? I can see it causing the 1 second delay before it downshifts if the pedal sensor is failing, but the downshift being so rough shouldnt be happening because of a faulty signal from the accelerator pedal right?

If the new aux battery doesn't help, maybe ill replace the accelerator pedal just to cover all my bases, and go from there. thanks for your reply.

 

The accelerator pedal is interfaced as a serial module, not wired as a simple ECU sensor. See your schematic diagram.
the down shift are rough because it takes place out of time and unexpectedly.
The accelerator is pretty much what controls downshifts besides low decreasing speeds.

 

You were right! A new accelerator pedal along with resetting the shift adaptations completely resolved the issue! Its crazy how much better the throttle response is with the new pedal as well. I always thought the throttle response was lazy, by design, because its more of a "grandpa car", and because i always had it in Eco, but I was incorrect. Even the tiniest press of the accelerator pedal now affects acceleration which also never happened before. Super happy that this issue is now resolved, i was starting to worry that it was a valve body issue inside the transmission.

One thing to note is that i initally just installed the new accelerator pedal, without resetting the shift adaptations, and it was only a little better but def didnt resolve the problem completely and i was bummed. I then thought that the adaptations might be messed up since they were based on readings from a faulty pedal, so i pulled out my foxwell and reset the adaptations to see if it would help, not expecting much, and took it for a test drive. I couldnt believe it, but it completely solved the problem! Downshifts and upshifts are now flawless, and can hardly be felt. I kept driving for about 20 miles to be sure, and shifts were perfect every time.

Thanks for your help @CaliBenzDriver, one more thing i want to mention, that you might get a kick out of, and shocked me when i was initially trying to diagnose this issue by cleaning the ground connections... the main 12v battery in my car is an H7 AGM thats original from factory with a prod date of November 2012!! Its still running perfectly fine, no voltage errors or codes, and we have had a few 0 degree days recently in chicago and the car sat for a few days at a time as well, and still fired right up after only 2-3 cranks. The one thing i do notice is, when parked with the engine off, the radio does shutoff after only 1-2 mins, which im sure is related to having such an old battery but thats not even that big of a deal to me. Anyways, AGM batteries are amazing, and that might be some sort of record (over 13 years on the same battery, with entire life in climate with freezing winter temps too). Therefore, im now also going to be replacing the main battery with a new H8 AGM, along with a new aux battery that i was planning on replacing anyways(im sure the aux battery is original from factory as well). I will say im tempted to hold off on replacing the batteries just to see how long these batteries will last, but not worth risking getting stranded somewhere because of a dead battery.

 

I am glad you've got proper throttle control again.

13 years on both of your AGM batteries is a really impressive lifespan.

It's better to change battery on your own terms than by surprise in the least convenient location.
After 13Yr... $200 battery is money well spent!

 

haha toally agree, ill at least make sure to test my old battery before getting rid of it just to see what its health is after 13 years, with 8 winters spent in chicagoland, and 5 winters spent in western new york. The rear subframe, and brake lines both had to be replaced due to being completely rusted through, but the battery made it through with no issue, haha! Ill post a picture of it here when i replace it, before returning it.

 

While we're here talking about batteries and Mercedes on salty winter roads ... CHECK SINGLE CHASSIS GND STRAP or add a secondary extra strap on top side like Japanese cars have.

GND Strap is located all the way under carriage near muffler at tranny bell junction.

You can test drop voltage between motor and chassis under heavy electric load.

 

Snapped a pic of it yesterday when checking to confirm that an H8 will fit on the tray (it will). I was actually wrong, it’s even older than November 2012, it’s from early July 2012 (27th week of 2012)!

It still starts the car after only 2 cranks in warm weather, and after only 3 cranks if below freezing (as of January 2026). I’m sure if it gets discharged just one time, that will be the end of its life (AGM’s hate being discharged) so it will be replaced in next few days.

My car is the last year of the E350 without start/stop so I’m sure that helped it live this long. Regardless, very impressive.


27th week of 2012!

 

thats the problem: it lasted too long without start/stop ("ECO").
Something has to be done to change that.

ECO requires an AUX battery with a collection of relays to switch power around. Be glad you don't have EngineCutOff.