Those of you with Distronic Plus on your 2010+ models, does the car automatically engage the brakes even when cruise control is not engaged?

I'm curious if the car will apply the brakes around town when cruise control isn't active.

 

My 2007 will automatically engage the brakes even when cruise control is NOT turned ON if it thinks you are about to crash...it issues a warning (3 beeps), brakes hard, tightens your seatbelt, adjusts your seat to the most ideal position for a crash, and closes the sunroof/windows. It might do more, but those are the things I've personally witnessed the car doing.

 

Perfect, that's the info I was looking for. Thanks for your reply.

 

My understanding is (and I'm far from certain on this) is that Distronic will apply the brakes,even when "cruise" is not engaged,in certain *emergency* situations.I think I read that that will happen if the computer interprets data from the radar system as meaning you're with a second or two of an accident.When "cruise" is engaged it certainly applies the brakes..and,IIRC,can even bring the vehicle to a full stop.

 

You've *personally* witnessed these things? Were you in an accident or did you see a film of some sort?

 

Early w221 cars with distronic will apply up to 40% braking force:

From 2008 owners manual:

When the distance to the forward vehicle is too small, the distance warning lamp lights up in the instrument cluster. If you approach the forward vehicle very quickly, you will hear a warning tone. If you do not apply the brakes yourself or maneuver around a sensed obstacle, the vehicle will automatically initiate lightbraking.

PRE-SAFEŽ Brake brakes your vehicle with a maximum of 13 ft/s2 (4 m/s2). This corresponds to about 40% of the maximum deceleration ability of your vehicle. This automatic braking is intended only to initiate the braking if the driver has not already done so. The driver must apply the brakes in order to prevent a collision.

In later cars (I think post face lift) the car will brake itself with up to 100% brake force.

 

A bit confusion here, early W221 do not brake automatically unless CC is on. From some point onwards, it could be 2008 but at least from 2008 onwards as the manual explains it the car does also brake automatically under scenarios explained above even if CC was not on.

The facelift gives a warning at 2.6 s before the estimated collision, at 1.6 s before collision the car starts partial braking and from 0.6 s before collision until collision the car applies emergency braking. The last phase is probably equal to BAS assisted emergency braking by the driver, i.e. full braking force but not the initial automatic braking from 1.6 s onwards.