How do comfort fit seat belts work?

[PJayUK]

I was trying to adjust the drivers seatbelt on my W220 this morning after my wife drove it last night. Whilst doing so I noticed that the height slider things on the door pillars, seem to have the ability to move up and down.

A quick check of the manual states that my car has "comfort fit seat-belts" (amazing after owning the car for 6 months I am still finding new features! )
The height sliders (is there a technical name?) indeed slide up and down under spring pressure but they don't appear to stay at a new position. In other words I can slide them up and down but they always return back to there original position.

Can anyone describe how they work and if (how) they can be adjusted?

 

[Cole@MBS]

There is a cable under the seat, (like a bike break cable) as you move the seat forward or backwards the cable adjusts the height of the seat belt slider! very simple but it works!

 

[PJayUK]

Wow that simple?

Does this also apply to electric memory seats (bit posh these SClasses!) ?

Cant seem to find a cable but I guess it will move up and down if I push said buttons!

 

[PJayUK]

Mmm, just popped out and took a look. The drivers side one works perfectly slides up and down with the movement of the seat. The passenger side however does not move and is stuck at the bottom of its travel

So, it looks like I have just found this weekends challenge!!

Any pointers guys on where to begin to diagnose this, any common faults?

I wonder though if there is a bum detector in the seat, would this feature only work in the seat is occupied? (I sat in the pilots seat when testing)

Any help as always greatly appreciated.

 

[television]

Just start the car up and run round and sit in the passenger seat, that will tell you if it uses the SRS sensor

 

[PJayUK]

Nope it made no difference.

So I need to work out how to diagnose whats going on!

Any ideas Malcolm?

 

[Cole@MBS]

Under the seat nearest the door at the front is where the cables connect, sounds like the n/s has popped off! your see the cable coming from under the carpet!

 

[PJayUK]

I'll have a rummage around later, might look a bit silly in my suit doing it in the car park!

Thanks everyone

 

[PJayUK]

Thanks guys, an easy fix thanks to your help!

Took all of 5 minutes to hook the end of the cable back on. All works lovely!