Dr Kananga

Greetings all!!

Just got myself a W251.
Slowly sorting out the odds and ends that were overlooked/neglected.

Since taking ownership, about 2 months ago, I've been driving and the transmission will stop shifting, up or down; might get stuck in 1st or 7th.
In the attached image, I was in 7th going 0 mph ¯\_(ツ)_/¯
This has happened three times.
I can't figure out what triggers it.
If I put the car in Park, it doesn't reset.
When I turn the car off and back on, we're back in business.

Maybe someone has an idea of what is going on...
Any insight would be most appreciated.
Thank you in advance.

PeterUbers

when has this trans been serviced? Sounds like a bad conductor plate; I would drain the trans fluid and drop the pan and check for debris at a minimum

when it is working on, does it shift smoothly?

Dr Kananga

Thanks for the insight.
When it's working, which is almost always, shifting is 100% normal.
If there was an issue with the conductor plate, would it trigger a fault code?

PeterUbers

not necessarily

sounds like your solenoids and clutch packs are ok; you may have debris in the valve body (conductor plate) and likely will just need a new one