HBerman

Complaint:
Delayed start-off from standstill and/or engagement jolt when coming out of the power-free state, or jolt when brakes are released (switch-on process).

I've had this issue on my 2013 E550-4M which feels like the brakes are sticking or not fully releasing when starting off. However, I found out today that this is a NORMAL effect due to an ECO implementation in the 7G+ transmission which saves .4Liter / 100KM and which reduces vibrations at standstill. Basically, the transmission is put into a standstill decoupling when in gear range D and stopped (like at a light). There is a delay of up to .2 sec until the transmission is re-coupled when the brakes are released.

The standstill decoupling (KID) is activated if:

. the vehicle is braked to a standstill
. the accelerator pedal is not depressed
. the brake is actuated strongly enough (250+ NM)
. transmission mode E is selected (also S on vehicles with 4MATIC)
. the uphill slope which the vehicle is on does not exceed 18%

One can override the KID function when stopped by depressing the "+" / "-" paddle on the steering wheel.

There is no way to turn off the function except to depress the paddle(s) at every stop.

This function was implemented starting in 2012.

ttsagris

My 2010 350 does something very similar. Will yours rev during the delay period?

ttoE550

This is interesting. I have a 2010 E550. When my brake discs were changed, I could feel the brakes release an instant or so after I lifted my foot. I thought maybe they were sticking or something wasn't done right. Sometime later, the sticky feeling went away and I no longer notice it. There must be something going on in the earlier models too.

BeachBunny

Interesting to see it show up on Mercedes (and be noticeable). I've had this on a couple of rental US-spec VW Passats lately and it drove me nuts. Definitely longer than 0.2 seconds on the Passat. Wifey's 2012 Passat doesn't seem to have this.

iGeorge

Thank you so much for this information! The engagement lag was annoying me greatly, only because I didn't know what it was up to.

Johnny Rad

This is great stuff. Wish'd I seen it years ago! Who knows if the OP is still around, but if they are - thanks!

My start delay / lurch is exaggerated when it's cold out, like maybe sub-45F, until the car warms up a bit. At it's worst, it feels like I've been rear-ended! With passengers on-board, it's downright embarrassing.

I've successfully worked around it by momentarily selecting N while stopped.

I'll try the paddles.

ghlkal

(Old Thread I know)

I agree. I have to try the paddles and see if that works.

Tump43

I had that on my 2014 E350. I took in to the dealer under warranty -- told them it almost killed me stopping then needing to turn out of the center of an intersection -- and they reflashed the system. Never had the problem again.

S-Prihadi

I know this is an old thread but I want to share a tip.
The stand-by de-couping "KID" mild jolt can go away if you do this while using HOLD brake at a red light.
- Stop at traffic light and gear still in D, get the brake to do HOLD.
- When light green , do not throttle, but instead press the brake again and the HOLD function will release and then press the throttle.
The delay between you undoing the HOLD and pressing the throttle will be a tiny bit more than 0.2 seconds and hence you won't feel whatever discomfort the KID produces.
Also since when one undo brake HOLD, engine RPM is still at idle , so it is very gentle.
If we release brake HOLD by applying throttle* ( *which you can ) , not only we can feel like sticky brake disc, the higher RPM hence more power ... is what caused the jolt and the intensity is depending on
how heavy footed you are on the throttle and what transmission mode was chosen at that time.

If non 4Matic ( mine ) and I am on transmission E mode where take-off from a standstill is 2nd gear by default, not 1st gear......and I stop at a toll both to pay ticket and somehow applied brake force hard enough,
as such brake HOLD function will kick-in and the KID too and then I kicked-down hard on the throttle after toll ticket payment , sudden KID release and sudden 2nd gear drop to 1st gear while throttle
pressed down 100%, will produce the worst jolt and a loud mechanical noise at the transmission or/and axle
If I tap the brake so slowly and NOT get into brake HOLD mode, no such discomfort will occur at toll pay booth even with heavy throttle take off.

To why a 4matic will default to KID even in transmission setting S is kinda weird don't u think ?
.

AndresInSpace

not to keep the revival going,
but I do get that 'HOLD Jerk' but I also feel the car 'clunk' into gear on an incline.. from park to drive or park to reverse. is this normal and attributed to the kid?

S-Prihadi

If you said incline, did you use your brake to stop any roll before shifting to Drive from PARK ? Use the brake first before you go into D from Park. Park position is a kind of lock mechanism.

I got it it from here, it has a photo of the said "pawl locking mechanism" : https://mechanics.stackexchange.com/...c-transmission
When you engage Park but do not engage the parking brake, the weight of the car is held by only the little parking pawl lever inside the transfer case, as opposed to the car's actual parking brake.
When you start your engine the next time, you can feel an unpleasant "thunk" when you move the selector out of Park, if there was even a tiny unevenness to the pavement.
This is because the little parking pawl is literally FORCED out of the lock, overcoming the weight of the car. It is always recommended to engage the parking brake first,
to let car's weight rest on the brake, before moving the selector into Park.

Hope that answer your question.

Scott Petermann

Im fighting this issue on my 2014 CLS 550 4 matic and have had hell trying to stop it. The dealer even did the bulleting per greasing the input shaft to make this sequence smooth. I had a guy from Europe code out brake hill assist and he tried to code out KID but it didnt take. The brake hill assist is off now though and the jolt is more perceivable. Prior to this i had different professional euro mechanics tell me i needed to new valve body, conductor plate, and solenoids so I did that and it didnt fix it. The car has 35k miles only. It pisses me off that MB did this. I even took the car to the dealer as I stated above and it didnt fix it. Mb felt so bad that they replaced a leaky oil line for free for me. The car does not do this in manual mode or as stated in this forum by pressing the -/+ manual paddles before it decouples. Im still on the hunt to fix this. Im working with this coder from Europe still and seeing if we can still code it out. If anyone has a fix for this issue please let me know. I will update as well after we work on it more. So upsetting this is "normal" according to MB. How could a company like MB send out their cars jolting like this and call it normal. Its insane. I dont think the 9G does this. I drove a c300 for a month while MB looked at my car in Austin and it was smooth as silk and did have brake hill assist. Anyways love some feedback from anyone who has fixed this issue.


One can override the KID function when stopped by depressing the "+" / "-" paddle on the steering wheel.



QUOTE=HBerman;6049640]Complaint:
Delayed start-off from standstill and/or engagement jolt when coming out of the power-free state, or jolt when brakes are released (switch-on process).

I've had this issue on my 2013 E550-4M which feels like the brakes are sticking or not fully releasing when starting off. However, I found out today that this is a NORMAL effect due to an ECO implementation in the 7G+ transmission which saves .4Liter / 100KM and which reduces vibrations at standstill. Basically, the transmission is put into a standstill decoupling when in gear range D and stopped (like at a light). There is a delay of up to .2 sec until the transmission is re-coupled when the brakes are released.

The standstill decoupling (KID) is activated if:

. the vehicle is braked to a standstill
. the accelerator pedal is not depressed
. the brake is actuated strongly enough (250+ NM)
. transmission mode E is selected (also S on vehicles with 4MATIC)
. the uphill slope which the vehicle is on does not exceed 18%

Im fighting this issue on my 2014 CLS 550 4 matic and have had hell trying to stop it. The dealer even did the bulleting per greasing the input shaft to make this sequence smooth. I had a guy from Europe code out brake hill assist and he tried to code out KID but it didnt take. The brake hill assist is off now though and the jolt is more perceivable. Prior to this i had different professional euro mechanics tell me i needed to new valve body, conductor plate, and solenoids so I did that and it didnt fix it. The car has 35k miles only. It pisses me off that MB did this. I even took the car to the dealer as I stated above and it didnt fix it. Mb felt so bad that they replaced a leaky oil line for free for me. The car does not do this in manual mode or as stated in this forum by pressing the -/+ manual paddles before it decouples. Im still on the hunt to fix this. Im working with this coder from Europe still and seeing if we can still code it out. If anyone has a fix for this issue please let me know. I will update as well after we work on it more. So upsetting this is "normal" according to MB. How could a company like MB send out their cars jolting like this and call it normal. Its insane. I dont think the 9G does this. I drove a c300 for a month while MB looked at my car in Austin and it was smooth as silk and did have brake hill assist. Anyways love some feedback from anyone who has fixed this issue.


One can override the KID function when stopped by depressing the "+" / "-" paddle on the steering wheel.

There is no way to turn off the function except to depress the paddle(s) at every stop.

This function was implemented starting in 2012.[/QUOTE]

Scott Petermann

Did you ever fix it besides manipulating it?