I have 2015 GLK 350 and am experiencing two issues with the driver's seat:

1. When bringing the vehicle to abrupt stops, the backrest of the seat moves forward coming into the stop and then moves back when the vehicle stops.

2. When going over bumps, the bottom and back of the seat move up and down.

Oddly, when I am not sitting in the seat and I try to move the seat back and forth or up and down, I can't.

Has anyone else experienced these issues? Is this normal functionality of the seat?

Of course, when I brought it to MB service, they said they could not "replicate" the issue. Par for the course, I guess......seems like if something can't be diagnosed with a computer, they can't fix anything anymore.

Thanks!

 

This sounds like the bolts on the driver seat aren't secure. Or, at least the rear set. Look at the seat frame from the drivers back door and make sure there are bolts in the frame mounts, and that they're secure. If they aren't, then check the same think on the passenger side.

Alternately, the seat bolts to the frame could be loose/missing. That's harder to check as you have to essentially look up from the rear footwell into the underside of the seat.

Either of these are extremely unusual issues to have unless you've had an accident or work done on the seats. It may be worth taking it to Mercedes for a safety inspection, just to be sure.