Hi,



Im new to MBWorld and this is my first post. I recently been dealing with some frustrating transmission issues that I could really use some advice on.



Symptoms Im experiencing:

When the car is fully warmed up, especially in stop-and-go traffic, the transmission jerks and hesitates when shifting up.

Sometimes, the gear indicator on the cluster goes blank for a moment when upshifting, and when it comes back, the gear number jumps up by 2 gears, followed by an immediate downshift.

On very rare occasions, when Im stopped at a red light, the car shuts off by itself and automatically shifts into Park.

Shifts are no big issues when cold.



What Ive tried so far:

I took the car to the dealership. They said they couldnt find any stored faults, but they upgraded the latest software to the transmission. This helped slightly, but the problem is still there.

I also took it to an independent transmission shop, and they performed a transmission fluid change, but this didnt solve the issue.



Additional Info:


Uphill sections, speed, and other situations that require mid-large throttle are most likely to appear. Plus it will appear when D hangs to R, and when driving at a constant speed at highway speeds, it won't be particularly impactful, but the gear display will be blank.

Not experienced at full throttle or just after cold start.

There a code detected starting with P when I changed the transmission fluid earlier, I forget exactly what it was I'll look for the file and update it later. They told me the problem was a "general error".

The symptoms are only present when the car is hot, especially in heavy traffic.

I don't remember how long it's lasted, at least a year or so, plus it shouldn't have been a problem when I first got the car.

Sometimes, like when it happens on the highway, I throttle it when it happens and can hear an sound probably coming from the exhaust, though it's possible it's not coming from the exhaust.



Has anyone experienced anything similar, or have any suggestions on what I should check next? Im really appreciate any insights or advice you guys could share.



Video:
https://drive.google.com/file/d/1Cr91pb4c7Hg-tab2k59EiNQjUOp-YqKY/view?usp=drivesdk

 

Sorry to read about your stock Mercedes troubles.

Your experiencing a combination of standard issues involving tranny, heat and voltage and networking.
Normally this is supposed to get seriously expensive. There are experimental shortcuts available to bypass unnecessary aggravations.

The best place to deal with these issues is a MB specialist.

The next step will have you produce a chassis scan report to assess what's actively dysfunctioning.

Q: when was the tranny ATF serviced?

One of the first step is going to go stop "$10k-oil-in-harness" with $50 CPS sensors.

+++ Tranny was serviced !
Are you confident proper ATF grade was used?
Were tranny troubles present before service or only afterwards??

 

https://mbworld.org/forums/w212-amg/...installed.html

 

What fluid was used for transmission service?

https://mbworld.org/forums/w212-amg/...id-change.html

 

This Mercedes trans is extremely sensitive to what fluid you put in .
Engine oil, tons of great options
Transmission fluid, only OEM.

Also try the sneaky trans reset
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Thanks for your reply!
I have tried two different brands of engine oil and three types of oil. I am currently using Mobil 0w40 esp. It feels a little less triggered than the liquidmoly I used before, but I don't think it has anything to do with the oil.
Changing the engine oil is too expensive and may not solve the problem at the root. As for the transmission reset, I currently don't know how to do it.

 

Thanks for your reply!
When I changed the transmission oil, I didn't have a clear understanding of this problem. I just told the person to check what the problem was, and if he couldn't find it, to change the oil for me. Unfortunately, after he changed the oil, I didn't ask him what oil he changed for me.
After reading your link, I roughly understood it, so I should try to replace the sensor and use the original oil now? But I went to MBservice once half a year ago, and they didn't reproduce my symptoms, so they just did a software update. But this symptom always appears when you don't need it. This symptom will only occur once or twice in a tank of oil, which is disgusting.
In addition, I see in other posts that it is possible that the valve body can also cause transmission problems. Does this apply to mine?

 

Thanks for your reply!
I am curious about what experimental shortcuts you are talking about.
Regarding your question, I am not sure that the person who changed my oil which not MB Service used the correct ATF. And the symptoms occurred before I changed the oil.