Glev

Looking for some help with diagnosing this problem I’ve attached below,

When I floor the car it kicks down and revs up as it should but doesn’t change, it just revs itself back down and then goes into gear ?

W205C43PFL

Uh oh, that is not good, I never heard of this issue on this transmission. What I am also concerned about is that it allowed the car to rev pass redline, that is bad, very bad. Especially if it does it often, plug a scanner in the car that can scan for codes and see what reports back.

W205C43PFL

Something must have gone wrong with the rev limiter as well, I would not drive the car until a scanner is plugged in to determine what went wrong, you might be damaging the engine by revving over the red line so often.

Glev

Have hard the car diagnosed with Mercedes sky scanner and no faults have come back, very concerned

W205C43PFL

When was the transmission fluid last checked and/or changed? It could be more than one issue, for one the ECU should not allow the vehicle to go past redline. I wonder if the ECU is faulty and is not giving proper instructions to the transmission and the transmission itself is fine.

Glev

You could be right, my first thought was that it may be slipping but I’m not to sure on that idea now. Also only does this under load when putting full power to the car from either a stop or slow crawl like in the video

W205C43PFL

I certainly do not recommend driving it aggressively until this is fixed, over-revving the engine can lead to serious consequence and jeopardize the life of it.

I wonder why there are no codes, they used XENTRY to check for codes, right?

Glev

Yeh used XENTRY system nothing came up, very strange

W205C43PFL

What year is the vehicle, how many miles and when was the transmission fluid last changed.

Glev

2016 only 31,000 miles, only had the vehicle for under a month so transmission service is my first step as it’s never had one done

W205C43PFL

When did this started happening after the transmission fluid flush? Was the transmission fluid done at a Mercedes-Benz dealership or an independent shop?

Glev

It hasn’t been done yet it’s booked in for next week

W205C43PFL

I see, hopefully there are no metal shavings in the fluid, hope it is healthy.