I had a similar error. " Service Required. Do not shift gears. Visit dealer!" error in first week with GLB and then came back in 10 months later... I restarted the car and drive with no problems and mine was happening at the parking lot at the end of the day when I was backing, most probably related to auto e-brake....MB help service told me even not to drive the car, but the problem was not the transmission.... At first time in service, they reported to MB and second time they updated the transmission software that supposedly solved the problem. However they never send me a notice that the software update was available for that issue until the second error....

 

That's interesting, thanks for sharing. My error was specifically Transmission Malfunction, but if your car also froze without ability to shift into D or N, then we share the same symptoms.

Tomorrow will mark 3 full weeks since I returned my beast to the dealer and they still can't figure out the problem. They've been trying to get help from MBNA who advised them to inspect the valve body speed sensor for potential damage or malfunction. That seems to have come up empty, and it has now been further escalated as an urgent matter to MB's engineering department. This is what I was told last Friday, so hopefully I'll get another update soon.

 

Yes, I couldn't change the transmission until the restart. The code was P07E600 Park Position cannot be deselected. A few GLB35's (8 speed AMG dual clutch) has the same problem. Software update for transmission control unit solved the problem:



And the software version details in another post:
https://mbworld.org/forums/glb-class...ml#post8597664

The MB service has not updated the other GLB35 owner, so she just had the same issue again with the same transmission malfunction error as yours:
https://mbworld.org/forums/glb-class...ift-gears.html

 

Ok but on mine, hey didn’t just update the software, hey replaced the entire transmission control module. I’m assuming the new one had the latest software or they updated to the latest software after they swapped out the part, however that didn’t fix the problem.

My error was similar, “Transmission Malfunction” but instead of “do not shift gears”, it said “stop vehicle immediately and safely”. So I’m wondering if these are 2 different issues.

 

Yes, it might be different. MB service has to identify the problem whether it is the software issue or not. In my case, MB took 8 months to come up with the software solution after first case is opened...

 

^^ Yes Serhan, it has to be different because I just got an update from the dealer and it's a doozy.

MBNAC had their engineers / techs troubleshoot for days and still couldn't figure out why the trans was faulting in those isolated instances. So they've authorized a full transmission replacement, which I was told is likely a $20-25k job if I were to pay out of pocket . I certainly didn't expect the fix to be something so major! The trans is on order and should be here middle of next week, which means my car will still be out of commission until at least late November.

 

I'm looking at used W205 9-speed transmissions with very low miles going for around $3-3.5k on Ebay so I'm assuming brand new they're $6-8k. So maybe this would've been a $10-12k job out of pocket, not $20-25k which is what my S/A told me.

 

Glad they finally did the right thing and ordered a new transmission and replace the defective factory one that you have been experiencing issues since even early ownership. Hopefully that should finally solve all the problems for you, which it should as like we all suspected, the transmission was defective from the factory to begin with and overtime the defect got worse which results in what you are experiencing.

 

*****Yea, the $20-$25k out of pocket is not even remotely realistic I would think.

I am only familiar with the older 722.9 7 speed transmission for high performance applications and there are two people in our local area (that I know of) that have had their transmissions rebuilt with really nice parts including better steels and friction materials plus valve body mods and re-programming to optimize shift points to the engine/turbo build of their car. At least with the 722.9, there are tons of them out there in service and there is aftermarket support and knowledge regarding higher performance mods to keep them alive behind some pretty potent powerplants, some producing in excess of 750 ft/lbs of torque to the wheels.

You could probably have your current transmission pulled, rebuilt with primo steels and really nice Raybestos GPZ friction materials, upgraded clutch packs, bigger pistons and fancy K3 clutch support, valve body improvements for longevity under high torque situations, all to street/strip or racing specs which would handle pretty much anything a stock or stage whatever motor could produce, have it re-shipped to you for your installer to put back in and re-program to torque/power curve that is optimal for your build, with proper TCU data uploaded to improve line pressures and shift patterns, etc.. for probably less than 10k, assuming you use your current transmission, and you had someone competent removing and re-installing and programming the rebuilt/upgraded transmission on your end, which is really important... Dunno if Southern Hotrod or any of the other high performance transmission places work on the newer 9 speed model, but rebuild kits are out there for that model, even if just stock steels and friction materials..

Remember, even if you get a used transmission with low miles it will probably have to be programmed to your car, it will not be just be remove the old, install the new, and everything just works, (unfortunately...). If your old transmission really was in bad shape, you'll be pleasantly surprised at just how much better your car runs with a fresh and properly set up transmission. Hopefully, everything works out well, regardless of who does the work, but especially a warranty issue handled by the dealer...

 

Hey Max, thanks for chiming in. I was only browsing EBay to get an idea of what a used transmission goes for, to get a ballpark idea of what this job costs to satisfy my curiosity. Based on seeing a used 9-MCT with only 3k miles going for around $3-3.5k, I assumed a new one from Mercedes would probably be at least double that and labor maybe $3-4k so I estimate this job would be at least $10-12k out of pocket.

Thankfully I don’t have to worry about paying for the new trans out of pocket, it’ll be covered under factory warranty and Mercedes is shipping the dealer the trans next week. My car ran and shifted flawlessly, I never had an issue with how it performed in the 4k miles I’ve driven it since new. But that nagging transmission malfunction issue surfaced 3 times within those 4k miles, so as others have pointed out it was quite likely defective from the factory.

 

Thanks W205C43PFL, I appreciate all your input and support in this thread.

While I’m glad the issue will finally be resolved, I just hope this doesn’t diminish resale value. It’ll also constantly be on the back of my mind that I got a defective trans from the factory and no longer have the original drivetrain parts it came with. All this will be mitigated if I actually get my allocation for a 2023 C63s as I’m first on their waitlist for their one and only coupe allocation. Fingers crossed!

 

I understand where you are coming from, It is definitely unfortunate that a "major surgery" like this one has to be performed and I am truly sorry that you have to deal with this.

I am glad to hear about your allocation, hopefully that vehicle arrives to you soon so you don't have to deal with this one anymore. Keep us posted!

 

Realistically, it won’t arrive until next summer. I submitted a preliminary order sheet to my sales rep for the 2023, they don’t officially have the allocation yet but once they do I’m supposed to get first dibs. I am going to sell or trade my 2021 in for the 2023 if they come through with the allocation for me. I’m sure I’ll probably take a hefty financial hit as used C63 prices have plummeted compared to where they were a year ago when Mercedes decided to suspend most V8 models. Back then, I had offers to sell mine $10k over what I paid. Now, used low mileage C63’s are going for well below MSRP. But mine was missing a few options I really wanted (especially the performance seats) so I’ll be able to build it exactly to my specs. Also, I really want to own the final model year.

I just got another update from the dealer. The trans was delivered today, almost a week ahead of schedule. If all goes well they’ll have my car ready on Monday.

 

I see, sounds like good news so far at least for the current car, please keep us posted.

 

I have a very disappointing update. So I was out last night visiting my cousin, as I was reversing from the street and into his driveway, the exact same thing happened again. The car was stuck in reverse in the middle of the street, transmission malfunction warning popped up, and it wouldn't shift into drive or neutral. Like all the previous instances, I had to restart to get it out of reverse.

At this point I'm not sure what options the dealer has. They got MBNA involved, escalated the case to the highest levels at AMG, then were given go ahead to replace the entire transmission. So I'm not sure what more can be done to fix it. And in the process of swapping out the trans, they damaged my car. Looks like it'll be going back to the dealer for the 3rd time for the same problem... I'm at my wits end here.

 

I am so sorry to hear that : ( That is the most frustrating thing ever for sure, makes me wonder if they actually did the physical swap.... actually maybe there is some conflicted data stored in the ECU that needs to be cleared as there might be a possibility that the ECU still thinks it has the old broken transmission and therefore not letting it perform to prevent further damage and or endanger you when driving (MB is all about safety after all form what I heard)? I am hoping clearing this conflicted data will let the ECU learn that the broken one is gone the new one is here so please don't limit the functionality of it anymore.

 

Thanks W205C43PFL. But one would think that clearing the ECU of any old data or codes would be on the checklist after a major job like this before turning the car back over to the customer. My SA called me back a few minutes ago, he is speaking with the lead tech who performed the job and will get back to me shortly.

 

I see, please keep me updated.

 

After speaking with the lead AMG tech, my SA told me the obvious, that it’s impossible for him to know what’s going on without me bringing it back in. Unfortunately I can’t drop it off for another couple of weeks. So I’m probably going to push back the bumper repair until this issue is fixed first.

 

So it looks like I’ll be dropping off my beast sometime next week to get it looked at again.

Being that the transmission was replaced with a new one by Mercedes, should that affect the resale value? Because I’m strongly considering selling or trading it in when they finally get it sorted out and i fix those cosmetic scratches on the front bumper (that repair will not show on Carfax as the dealer is paying for it).

 

Most likely will show up on the CARFAX report for replacement of transmission.

 

Yes, I figured that’s very likely but it will be as a collision / accident free car on Carfax.

 

Lemon law that car.

 

I will give them one more opportunity to fix the issue. The plan is to drop off my car back to the dealer early next week. If the error resurfaces after this time, I will have to consider all my options.

 

Well since they already ruled out the entire transmission, most likely a fault externally. Our vehicles have over 60 on-board modules that transmit signals on multiple CAN networks. When performing a control unit call if the “tech” was wise he would think outside the box and look at inputs from other modules going into the transmission. What is the fault code that keeps popping up? There has to be a fault stored in multiple modules EVERY time your trans goes into limp-home mode. Hope this helps! Doesn’t seem like a complex diagnosis in my opinion.