Johnny Rad

I've got a 2012 W212 E550 4Matic and have two questions.

1. Does this car have variable assist steering? For example, does it get firmer as the speed increases? It feels like it does, but getting a history lesson would be cool.

2. I understand that our E/S button only affects the tranny (bummer!). I tried the flappy paddles this week in S, but still thought the gear changes were about the same as in E.

thefisch

Think your right about the steering but don't know any history or details there.

S mode for the tranny starts in 1st gear instead of 2nd and is supposed to hold the gear until an higher rpm. Since the default after each startup is E instead of remembering your last setting, I drive in E most of the time. But S mode is handy when you want a more violent start off the line for some fun with the V8. Paddles are useful for passing at speed (usually two clicks down).

Johnny Rad

I use the paddles for downshifts and floor it for passing.

I have to plan really, really far in advance for downshift paddling - nearly 1sec per gear and often look for 3-4 gears lower from hwy speed.

reckrab

Unless I completely misunderstand the system the E/S switch only controls the shift points. Using the flappy paddles changes gears manually so the E/S switch should have no effect when using them.

thefisch

For mine, it takes about a second to react to the two clicks when passing at a normal speed.

konigstiger

Direct steering with variable steering assistance, no unique service other than checking level view service sheet here https://mbworld.org/forums/e-class-w...ml#post6196232.

Transmission (see post 4): http://www.benzworld.org/forums/w212...schmutton.html

thefisch

if you feel your tranny has a mind of its own, try doing and ECU reset. Here are instructions that I saved on my phone for quick reference. Sorry, can't remember who posted them to given them proper credit, but they were posted on this forum or the other one. Did this after I bought my car and could tell a difference.

1. Get in car and close the door.
2. Turn key to position 2 (or press the start button twice) with feet off the pedals, i.e. do NOT start the engine.
3. Floor the gas pedal and keep it down waiting 10 seconds when you will turn the key to position 1 (or press the start button once) still keeping the gas pedal down.
4. After key in position 1 lift you foot from the gas pedal and wait about two minutes. In my car the cluster goes black after about 20 seconds but then pops up again after about two minutes. Anyhow, wait two minutes no matter what happens.
5. Turn key off.
6. Go test drive it. You will have a different car to drive.

As I do it I don't open doors or anything while I wait that two minutes. Just listen to the radio. I don't know if opening the door would cancel the reset but it has worked for me every time and I have not opened doors during the reset.

This is a simple procedure. It will sharpen up your throttle response if you have been mostly driving slowly.


1. Turn the ignition key to the on (not start) position.

2. Press the gas pedal to the floor and hold for five seconds.

3. Turn the key to the "off" position (don't remove the key), then release the gas pedal.

4. Wait at least two minutes for ECU to reset.

Johnny Rad

FYI: Seems ~10mph is when my steering goes super light. Above that, it's heavier.

Nothing wrong with all that, just saying.

Wished it firmed up more at speed, but it's fine.

Trancebolt

Hydraulic speed assisted steering; Indeed sir.

E is programmed to run stretching gears out the most, and to not allow slip. It also softens the cars feel. (pre13)
S is programme to memorize your driving style, rev faster, and allow 10% wheel slip; also feels harsher and more solid.
The paddles are also affected by which mode your in; The sound and rpm rate of speed will prove it. My 0-60 is actually .3 faster in E. People disbelieve me. S is better for tricky handling, and sound; E is best for sprints and stability.
Check out the manual. It doesnt indicate that E learns your driving, only says S. (btw mines a bluetec so it starts in E in 1st too)

As far as the paddles, Its not meant to be shifted AT the shift point. You shift while accelerating and let of the GAS at the shift point, and it then snaps down. Its a unique bespoke mbz transmission. Dont let the bmw fanboys tell you it doesnt work right. Its just overly complicated and touchy; Also I imagine theres a reason renntech offers this,http://www.renntechmercedes.com/www/node/524 =D Surely its necessary at one point. I cant defend the tranny as a whole.

I recall reading an article about the Siemens VDO valve ecus being faulty; lawsuit status from mbz

Alex.currie44

First of all yes it does but it is speed sensitive steering. Higher speeds mean less boost.
Second, an ECU reset does wonders for these cars.
E/S is a start selector feature really useable in snow.
In E it starts in second gear and shift points are higher this reducing fuel consumption. When reversing starts in a taller gear using the second reverse gear which is good in snow as well.
S starts in 1st and the shorter ration Reverse.
There are two reverse gears in the tranny.

iGeorge

The steering seems to go light below 10mph or so; the system is electric on the 2012's I think, so it would be interesting to see how it affects the maintenance intervals.

This is only my impression, but when I try to use the paddles to downshift, the transmission reacts well, but the engine seems perfectly content at the higher RPM, so the engine braking effect is next to nothing.