2011 - W204 - Stuck in sport mode?

[Moocow]

Think this is related to suspension. I have a w204 Coupe with the sports agility package (sport button on dash not on the gear stick surround - changes suspension as well as the throttle/gear changes).

When starting up the vehicle it is in the default "Eco" mode as normal, however after a short drive 10 - 20 metres the car will switch to S mode automatically and the suspension firms up of it's own accord. It will stay this way until next start up sequence of the ignition and will not allow switching out of sport mode at all by pressing the button the dash.
From what I can find this is either a faulty damper causing it to switch or there is the possibility it is a levelling sensor which is attached to the suspension has become broken - either electrically or physically.
Does anyone know how I can do some basic diags of what is broken without diagnostics computer (hoping it isn't electrical issue!) - for example what is the location of the sensor on the car which dictates the ride height so I can at least do a visible check to see it's not something just come undone. Is it a specific wheel corner that it can be found?

I know some people would love the function of Sport mode by default, but it's not an enjoyable experience on potholed lanes with hard suspension

 

[Moocow]

Ok, fixed this myself this morning. About an half an hour with basic tools - jack with Merc adapter, jack stand, socket set, flashlight and torque wrench (to refit wheels afterwards)
For info and anyone searching in future:

Each corner has a sensor that detects the levelling function of the suspension.
You will need to remove each wheel and check that the sensor is properly attached and functional.
On the rears, this is at the top (12 o'clock position), the sensor runs at 90 degrees to the wheel face and you will see a little ball jointarm that goes from the sensor to one of the suspension arms. Check the arm is not broken or has come detatched. You want to also check the sensor has not become unplugged while you are here or that the wiring is damaged.

The front, they are slightly different - again you will need to remove the wheel to check, this also helps as only half the arm is visible on the front with the suspension extended. Again at the top (11 o' clock position roughly) you will see a little black plastic arm with ball joints on it in the shape of an inverted J on it's side. Half of it is behind the wheel liner along with the sensor unit itself so either remove the liner or in my case I just felt around for the arm connection being sound.
In my case the front left wheel little plastic arm had come off the lower mounting point. These are easy to click back into place without any special tools. It pops on, but make sure you push it again so that it goes over the ball completely - you will know its correct as the arm will lock in the upright position relative to the height of the suspension and should be able wiggle back and forth slightly but not left to right.

Test drove for 5 miles and now have comfort mode when it again. It appears if even one of them is out the car defaults to sport mode despite the other three being all secure and sound. I can only assume a pothole caused this - wouldn't be surprised considering the state of the roads over winter.

 

[C280V6]

Hi, I have same problem but have discussed this with main dealer and specialist but unable to help or resolved. Do you know a specialist (or garage) that can do the suspension checks based on your discussion above or have resolved this issue before?

 

[alexanderfoti]

We have done loads. The level sensors are usually the common culprit but not the only thing that locks sport mode on.

 

[C280V6]

Thank you! I’ll show this thread on the last specialist garage I used and hopefully they can resolve by just checking this common culprit and clicking it back into place.