davidbijan

I recently started to use the hold function at stoplights, but im a little paranoid that it will disengage if im rear-ended and ill possibly lunge into oncoming traffic. Not that any of us want to put this to the test, but does anyone now if it is as secure as holding down on the brake?

K-A

It is designed to go into Park I believe, in the even that it is disengaged for any other reason than by hitting the gas, or pressing the brake hard, again. In that case, it would actually make it probably a safer bet than holding the brake down with your foot.

Live Oak

Doesn't go into Park.

Don't know how strong a braking, though.

hyperion667

I've always wondered what would happen with
the hold on, if you got romped from behind......

so it would stay engaged? seems like it would or why have it? aside from
the nice rest for the foot......
I also recall reading somewhere that the hold could put extra, un-needed
stress on the calipers or pads? or am I nuts?

konigstiger

Braking effect cancels, and HOLD function deactivates when you depress the accelerator pedal to pull away. This implies it will not disengage if hit from behind. But if feature senses skidding, it will automatically deactivate triggering warning tone and display message.

Live Oak

Is that one question or two?

enzo thecat

What is the "Hold function"?

And while im at it, what are the triangles on my side mirrors that light up when I drive in my addition?

aeggroup

It's called "Blind Spot Assist". Read your manual.

MagicJack

When you get hit from behind, eg 45mph by a dodge ram pickup, your foot does not stay on the brake pedal; no way -- your leg is catapulted back and you'll have a bruise on your calf the next day from it hitting that compartment latch on the bottom of the seats.

Your car does go through the intersection.
The seatbelts clamp down on you like a strong wrestlers bear hug.
Your head gets jolted from the neck pro headrest popping forward.
The emergency flashers automatically go on. You unlatch the seatbelt's chokehold in order to breathe.
In 15 sec a voice comes through your car speakers stating 'deployment of MB SRS devices was detected. We have your location, do you require police and and ambulance?' You say 'yes'.
You stagger from you car, shaken, but uninjured.
In two minutes your wife calls you from work and says he water broke. Later that night you become a dad. And, you're glad you bought a Mercedes.

That was a hell of a day -- the memory of it still shakes me up.

To answer the question, both you and HOLD will disengage the brake in a rear impact, but given how hard HOLD clamps on the brakes and its delay in disengaging, it will likely hold you in place better than your foot.

B6JoeS4

What MagicJack said.

In a mild rear end collision, your foot will not be able to keep the brake depressed. a 10mph impact makes your 10lb head weigh roughly 170lbs in just 60 milliseconds. The average human leg weighs about 20lbs so in a 10mph impact, your leg alone is experiencing the same 15-20g's as your head. This means that your leg weighs about 340lbs!!!!

That is a worst case scenario. There are tons of mechanical variables. But you get the idea.

LaicepsYdobon

You want it to disengage in the event of a rear-end collision. By having the brakes disengage the car behind you will push you forward thereby dissipating some of the energy of the crash. By your car offering less resistance of being pushed the less violent the crash will feel on the inside and the better your chances of surviving. Once your car is being pushed from behind it is a different story where you are being pushing (into traffic or the car in front of yours).

Diesel Benz

I wonder if I understood this view correctly. If the car is steady, held with the Hold function, the car would likely suffer more from the rear end hit if Hold keeps brakes on but anything that keeps the car accelerating less from the rear hit, would reduce stress for the passengers. I believe most often the passenger safety comes before the car damage concerns.

Diesel Benz

I'm glad to hear that story from yourself (I'm not glad about the accident but it could have been that you would not be here to tell the storey any more yourself).

LaicepsYdobon

Yes; you understood my point. It is better to have the car move with the direction of the crash, for the sake of passenger safety, as opposed to try to stop the inert body in motion (the other vehicle) which would result in a violent transfer of energy. A Mercedes will always sacrifice itself to keep its occupants unharmed as much as possible.

LaicepsYdobon

You are nuts Seriously; it doesn't put extra stress on the calipers/pads. If you have the hold function activated it is like you pressing the break pedal. Up to a certain point the more you press down on the pedal the more firmly the calipers grip. After a certain point the calipers are gripping at a 100% so it is irrelevant if you keep on pressing the pedal harder, the calipers can not grip any stronger. When standing at a red light you can hold the break pedal as you would normally with one foot and the calipers are gripping at 100%. You could also stand on it with both feet and the calipers would still only grip with 100% (like if you would do with one foot only).

stemags

Forgive my ignorance(and for you know-it-alls who love to tell people to read their manual) Whats the deal with the hold function,,,and is it in all the w212 chassis?

LaicepsYdobon

The next time you are at a red light double tap the break pedal. You should see a HOLD indicator appear on your instrument cluster. You can now remove your foot from the break pedal because the car is applying the breaks for you. To disengage it just start accelerating normally. I believe this feature is standard on all US spec cars.

And if you want to become a know-it-all also

http://www4.mercedes-benz.com/manual...97e38685.shtml

stemags

Ohh very cool,,thanks Jersey..things that make you go "hmmm"

PHML

i tend to use this feature every chance i get...love it!!

axhoaxho

I like the Hold function, now it becomes my second-nature to engage it whenever I am stuck in traffic for long.

stemags

Ok so there I was tapping the brakes at a lite...the hold didnt engage(prolly not doing it right)but the nummy nuts next to me thought it was time to race
I assume you must be fully stopped?Do you need to use two feet?

PHML

Yes...u need to be fully stopped (but not fully depressing the brake pedal to the ground....just enough to stop the car from rolling)....then do a quick stomp of the brake pedal to the floor...the HOLD should light up on your display console...then let go the brake pedal. Press the gas to dis-engage the HOLD.

stemags

Ok...got it...works like a charm thanks so much...this will be quite useful when stopped on a grade. Another "hmmm" moment for sure.

LaicepsYdobon

Once you got it to work its easy to get it to do it again. It's the first time that's the hardest...

listerone

Is this to mean that what you've described actually *happened* to you? If so,exactly what were you driving and how was it equipped? I have mbrace and Distronic Plus and have been curious about what,if anything,they'd actually do (real world) in a serious accident.