andwhysee

Hi Guys
I have a 2012 ML350 with 79k miles. I bought it used in November 2019. I had No issues at all. But past two weeks I had a couple of problems shifting from Park to D or R. It first happened a week ago then It just happened again now. I couldn't shift from P to R. Well I was able to shut off the engine, restarted then the shifting work. what could be the problem? I don't see any warning lights. It's been cold lately here in DC. The car starts fine, even though I just noticed a little hesitation when I turned the key few minutes ago. Please help thank you!

ml3504matic____

Replace Auxiliary Battery.

andwhysee

now my car won't start. is this main battery or the aux battery??

OnlyGerman

Aux battery

Gio Sayah

Any updates?

chriswhv6

Started having the exact same problem with my ML 350 Blutec 2013 model.
About 2 months ago is when i first noticed it started to happen.
Has only happened in total maybe 4-5 times since then and only on cold first start ups.
The only way so far to get the shifter to work is ill have to switch off the engine, open the drivers door, close the drivers door and then restart and then it seems to work normal again.

There has been no warning messages on the dash and about 15 months ago i had got the Aux battery malfunction warning (which the vehicle never did the shifter issues back then) and had the battery replaced brand new at a Mercedes Benz Dealer ad never seen the Aux warning message again since then.

Could this be a Keyless Go or Fob issue maybe?

Gio Sayah

i have finally fixed the issue ( 2 months problem free so far) posting a detailed troubleshooting process soon..

asinnj

Can you share your findings. I’m having same issues

chriswhv6

Mine was the main engine starter battery that was causing the problem.
It was its original battery in the ML from factory built so almost 10 years it lasted.
The voltage was dropping way below when trying to start and it would cause a issue with the computer that tells the gearbox to shift gears from the lever.

Had my battery changed and (knock on wood) the problem is now sorted.
Done at Mercedes Benz dealership supplied & fitted for $1,200 Aus dollars.

Gio Sayah

My sincerest apologies for the late reply i gad a lot going on for the past couple of months.
Okay guys so back when this issue happened with me i tried literally everything that's been written on the forums : main battery replaced, aux battery replaced, key fob batteries.. None of this helped i ended up dismantling the SCM and turns out the outlet where the shifting stick gets pluged into is tin soldered on the SCM board and the solder with chipped and had broken off. (Shown in red in the attached photo) so all I did was re-weld the part that had been broken and disconnected. And i have been driving my beautiful suv problems free. I am willing to help anyone who's having this problem in depth through whatsapp if any of my explanations wasn't clear enough : here's my number +9613426693. I know it can be a hassle 😂 I've been there.

CaliBenzDriver

At last someone who's not afraid of putting its solder iron to the car... two of us! 👏

Are you sure now SCM perfect or "Direct Shifter" still a bit goofy at time with soft-crash no shift until restarted?

Another seriously bad module that is scheduled to cost you dearly is ISM : gearbox shifter famous for "Limp-mode" and "No-Crank".


ISM money maker

Many thanks to Juan @juanmor40 for spotting this SCM thread .

Joey M

Do we have a write up on how to remove? I’ve been able to find so little about this subject, feel in the last 3 years this is the closest!