Cinch actuator sometimes not working on power lift gate

[A-Wimoweh]

I've noticed that sometimes when I close the power rear hatch, at the very bottom it will make a loud sound and pull it just abit tighter. Other times that does not happen. Might be related to cold weather, and if the car has been warmed up it usually does cinch. Seems to not cinch it when the car is cold. Either way, I do not get any warnings that the rear hatch is open.

Anyone else notice this? I think I can hear the hatch rattle abit when going over bumps and it has not been cinched down.

 

[commasign]

I think you may be developing the issue described in this thread:

Rear trunk won't open

 

[EVCarGUy]

Cinch motor and hatch latch are common failure points on the S. Thank Mercedes for them.

 

[Oldschool496]

Warranty or not get it looked at right away. Emergency release fails also many times, the process to get in to replace it is from the stone age. Go in from the backseat, they used a sawzall on mine and replaced upper and lower deck trim and cinch motor. The latch attached to lower deck of the car they did not replace and it still has teeth marks (minor) from the sawing.

unfortunately its the only way to get in to most if not all.

 

[A-Wimoweh]

So I took it in this morning for my scheduled service appointment. Probably one of the worst possible days, but I took it in early. I was able to demonstrate the behavior of it not whirring/cinching multiple times in a row. The tech's explanation was that the cinch motor does not always operate every time, only operates if it did not get a good close. So I guess that's it.

 

[JPP]

So I took it in this morning for my scheduled service appointment. Probably one of the worst possible days, but I took it in early. I was able to demonstrate the behavior of it not whirring/cinching multiple times in a row. The tech's explanation was that the cinch motor does not always operate every time, only operates if it did not get a good close. So I guess that's it.

...not sure 'that's it'...but you have logged it into service so when it fails (???outside of warranty) you have documentation.