Great info - thanks!

I only care about updating my car so if it only works for limited time that's OK. I mostly want to update the audio and transmission software. If I get really ambitious I might look into ECU tuning as well.

 

I bought '07 E Class Bluetec diesel ( with 52,000 miles ) in AUG, and kept scratching my head with the gear changing antics.. I only drive the car occasionally ( 1,500 miles since AUG ), but have gotten used to the shifting "pattern". I now think the gear change before it happens ... boop, boop, boop, here comes 4th .. boop

From what I understand, MB dealers applied "prgramming fixes" to 7G gearboxes for warranty issues. BUT, when warmed up, mine makes no difference between C and S modes. Exactly the same operating characteristics. By chance, the dealer I use ( but did not buy car from ), did service the car at 43K miles for trans warranty, at which time they changed tranny fluid. I have heard from others that C & S differences went away after dealer servicing .. "back when".

Yes, mine will occasionally KICK going back into FIRST gear ( at 5 - 7 mph ) when car is cold. When warm, that goes away. It's a decent kick, thank you..

Sounds like all U guys have gasoline engines. With the 4500 rpm redline, and MONSTER torque from 3 liter V-6 diesel ( 400 lb-ft torque at 1600 rpm ), it's hilarious ( like being in F-1 car ) when doing a full on acceleration from standstill. Talk about short shifting up through the gears ( literally ) like 1-2-3-4-5 and it's 80 mph.

Have learned to GENTLY bump the throttle to not have the computer, continuously variable turbo, and all that help confuse the controls into figuring WHAT gear to go to on downshift ... again the silly torque makes a single downshift MEANINGFUL. Slamming the throttle down takes the computer and turbo awhile to figure out what's going on. It never seems to get sorted out. Gently, but firmly, is the answer. Doing a drag race from 10 mph is much better than from ZERO..... Hah hah .. I blew off my neighbors Lexus 3.5 liter V-6 with 10 mph start Finally lifted at 120 mph with him 2 car lengths behind.

Never had a diesel before.....clean diesel is another world. Just got 39.7 mpg on 400 mile Interstate trip too. I followed MB's development of this car ( with 100,000 mile enduraance run at 140 mph average in 2005 ), so I thought it was time to "try" this new twist to high efficiency.

8 speeds ,and all that ?? .... why not just go to the CVT transmisson like Chrysler uses on some of it's vehicles... newest version of the old DAF rubber band tranny .......... engine stays at ONE speed for MAX efficiency.

Can U IMAGINE what it costs to overhaul a 7 or 8 speed gearbox? FUGET about it.

 

To those who do not like the shift pattern of 7G trans from car that someone else owned before .... ADAPTIVE logic will ( should ) change with time, as tranny gets used to new driving patterns.

I will ask dealer ... what's what with the programming in my 7G

THANX TO ALL for the interesting info. Yeah, I find MB engineering to be quite **** ... but technically interesting as retired aero engineer. Just had to spend $1,600 to replace 2 piece driveshaft center bearing and rear half of driveline ..... that ticking sound ( like electrical relay going nuts ) inside the center console was drive shaft bearing snapping back and forth on rear prop shaft machined hub.

I still really like the car so we'll keep going.

 

The diesels run a different map on the 722.9.

 

Been running in C mode for a week now. Suits me just fine in traffic. Much better!

 

Glad to hear!

Does yours have the "hill assist" in "C" mode? I thought all the 722.9 equipped cars had hill assist in C mode. Apparently mine doesn't by default, and haven't figured out how to enable it in STAR.

 

I have not noticed John. Will revert.

 

John, I read some posting on the forum (IIRC by Russell O., but can't be sure) that said the "hill assist" was caused by hardware in the 722.6 that was removed in the 722.9 for space reasons, not that it was software or STAR related.

 

Report back as promised. My car does not seem to have hill assist in "C" mode. Runs back if you don't keep your foot on the throttle. Nothing about it in the owner's manual.

 

BTW - Me & the 722.9 are getting along just fine now. I've unlearned my 722.6 ways. We kind of ignore one another now & just get on with driving & all is seamless & well behaved.

 

That is good news, but I am thinking that you miss the 722.6 just a little

 

That is probably true but I like the fuel consumption the 7G gives me with an extra 100hp.

 

I've been running my transmission in Comfort mode with a very light throttle for the last 2 weeks, and the transmission behavior has changed considerably. Shifts are smoother and at lower RPMs. The downshifting surges are barely noticeable now.

The car is a lot less edgy and a bit less fun, but I guess the tradeoff is worth it. I hope it's not an intermittent fault with the valve body that corrected itself.

 

Mr. Ruck,

Had occasion to again drive mom’s 722.9 while visiting on family matters.
Although counterintuitive to my ingrained and admittedly stubborn logic, C mode did indeed prove more settled when chauffeuring kin about.
Damned if I don’t continue to learn worthwhile intel from you and this forum’s other active participants.


*off topic*

Driven our new GMC almost 800 miles.
Was initially reluctant to specify a 6L80 behind its 5.3L Gen IV on the option sheet, since I’d grown accustomed to the erstwhile 4L60’s ratios and shift characteristics.

Background:

4L60 = 3.06/1.63/1.00/.70 (w/3.73 differential ratio & 31” tire diameter).
6L80 = 4.027/2.364/1.532/1.152/.852/.667 (w/3.42 differential ratio & 31” tire diameter).

Notwithstanding the de rigueur torque management (spark advance and throttle retardation ‘features’),
there’s a “Tow/Haul” switch on the gear selector that dramatically alters automatic shift and torque converter lock-up programming.
Rather like C/S mode multiplied by a factor of at least 3, or the DIY valve body shift kits of yesteryear.
Don’t much miss those ATF showers though. Fixing to renew its Dexron-VI after initial run-in regardless.

Seldom went further than 16 mpg (14.7 L/100km) sans payload with the old 215 HP turd.
Now consume Chevron at 21 mpg (11.2 L/100km) with the new 325 HP drivetrain at a steady 75 mph; ~1900 rpm.
Rationalized to the accounting department that it’ll pay for itself after a few years.

More available ratios are almost always better, given the proper combination.
It’s certainly no DOHC M272, though GM’s venerable small-block continues to earn its keep for millions of U.S. tradesmen.
Its CAFE tariff circumventing variable cam-in-block valve timing and seamless electrohydraulic cylinder deactivation competes admirably with marques from other shores IMHO.

Already fitted HD Bilstein dampers, stout aftermarket anti-roll bars and, of course, mud flaps.
Will ditch the junk OE tires (tyres?) for suitable Michelin’s come spring.

http://www.gmpowertrain.ca/Product/5...%20Summary.pdf

 

Looks good to me. Indeed a lot more frugal than the old banger. There is nothing wrong with that mill.

Trust she provides sterling service.

Mud flaps indeed - us both

 

I wish all vehicles had mud flaps. They help protect others from stone damage & spray in wet weather.

 

+1 to that! The CLK mud flaps actually look good as well!

 

Hi All

I got a problem in my C230 with 722.9 tranny.

I have never felt any issues with my tranny but few weeks back my indy mechanic took my car for a test drive and he advised that some adaptation is required and he did that by connecting it to the system and said that you'll feel the shifting is more smoother now. But i don't know, i never felt any change in that, but from last couple of weeks what is happening is, especially at lower speeds (in traffic), when we have to accelerate / decelerate frequently, car jerks, as if gears are slipping. In another way, if i remove my foot off the paddle to slow down and when again press the paddle, it jerks like gear got engaged again. (tat's the best i can explain). The same thing happens when i slow down, take some turn and accelerate again.

I went to the same mechanic and he said he need to check the tranny, may be it has gone bad.

I have read all the threads but i believe, may be my case is a bit different. Here are some of the things i would like to highlight & ask.

1. I am the second owner of this car & this is my first MB. It is having 119K Kms on ODO and i have no idea if the transmission fluid was ever changed, because when i bought (116K on ODO), i got all the fluids changed by the indy mechanic except for tranny, as he said that there is no need to change the tranny fluid in MB, they are for lifetime (My conscious never accepted that) somehow i agreed to him (Though its a MB technology).

2. What is Adaptation ? Does this problem came out becoz of that ?

3. My Engine mounts also needs to be changed. Does this makes the transmission to misbehave. (I hope not).

4. What should i do next.

What i am thinkinig is, before just blindly going for a tranny overhaul (which is very expensive), should first get the Transmission fluid flushed and put the new one, change the filter, get the software check for TCU or get it reprogrammed (whichever is right) and see if the problem is gone or not.

Your expert advise is required.

Thanks in advance.

 

Bad engine mounts will effect apparent transmission behaviour.

Adaption is a word used too loosely on the forum. It is really setting up everything to talk to one another in laymans speak. eg. ECU to TCU etc. Many Benz systems auto adapt given time. It is also used in the case of the transmission to indicate set up of change pressures etc.

First thing to do is change fluid & filter & make sure you have the latest software flash. Don't do anything until that is done.

Change those engine mounts & the rear tranny mount if soft or damaged. Change all 3 together.

Sometimes minor jerks from throttle on to off & on again can catch out the converter lockup clutch.

Don't listen to any idiot that tells you that these transmissions are filled for life. They require a fluid & filter change EVERY 39K miles or 60K Km's.

The later 722.9 software flashes smoothed out operation & now inhibit a change down to first gear when stopping until the vehicle is at rest. The huge ratio change from 2nd to first always caused a jerk with the old software.

 

BTW ~ make sure you drain the torque converter as well.

 

Thx Glyn.....will update the outcomes soon.

 

Later MB models rely heavily on electronics. Proper diagnostics are made with Mercedes proprietary diagnostic tools, most of which, to my knowledge, are unavailable outside of MB dealerships.


The transmission IS NOT sealed. As such, it must be serviced just as another poster pointed out. Too early for engine mounts to go at your mileage. Get a second opinion.


Transmission is described as 'adaptive' in that it memorizes your driving style and shifts accordingly. Memory is not permanent; adapts continuously - delayed shifts for sporty driving, for instance. The 'adaptation value' can be checked and adjusted at the dealership. Involves pulling codes and using MB-supplied tools.


Drawing from your description which is really not clear:
a) either your tranny is arbitrarily shifting down. You can verify this by watching the RPM shoot up, or
b) the engine is free-wheeling (high rev again, but without power to the wheels) before you feel the tranny connect. That is a slipping transmission.


Issue a) is generally addressed by diagnostics, leading to adaptation value review/adjustment. Might need a replacement 'electronic conductor plate' (MB terminology).
Issue b) addressed by correcting fluid level - again, after reading diag codes. I believe MB tools can tell if under- or over-filled; always checked at 80 degrees F. Fluid temperature is measured using an MB provided tool.


One last word: Let your original mechanic learn on someone else's MB. Seek out a reliable MB dealership of good repute. They have the tools!

 

I've seen many shot engine & tranny mounts at 100K Km's

Checking for stored tranny codes with a Star or Snap-on Solus or similar that is capable of reading MB transmission codes is a good idea.

The most common cause of transmission flare or loss of drive is a clogged filter and/or low fluid level.

Conductor plate issues are usually accompanied by turbine speed sensor implausible codes which can be speed sensor ring clearance issues or conductor plate.

Fortunately most transmission issues engage limp mode.