Hey Guys,

Been a while since I've been around, hope you are all well,

So I have a confusing situation I need advice on.

About 2 weeks ago, my 722.6 was starting to shift a tad sluggish, I think all the inner city traffic driving caused the gearbox to adapt to that scenarios.

So got in the car, performed the reset procedure, waited 2 min, started and drove like a maniac in the hope that the car will adapt to a more aggressive shift pattern,

Unfortunately a day or two later, I noticed that in the morning when driving from cold, after about 5-8 min of driving within a certain temperature range(I could be wrong) the car seems to jerk, lunge forward under light throttle or lift off and get back on the throttle type scenarios and make that droning sound or jerk under braking, however 2 min after that its instantly fine and will be fine for the rest of the journey,

Even if the car stands for a while, but doesnt get completely cold like in the morning, I don't get those symptoms,

My natural assumption was by performing the reset I somehow messed up specific values/settings/adaptions but only within that specific temp range,

So I performed another reset again today to test out my theory, I reset the adaptions, and instead of driving like a maniac, I drove normal, and what I found was upon cold start, I don't get any symptoms anymore up until around 15 min of driving, then I start experiencing more prolonged jerking and droning, until the car is completely warmed up.

My question is, can my reset procedure have erased values to cause the lockup clutch issues experienced above?

Does the gearbox have two modes, one for cold and one for up to temp?

If I reset the adaptions when the car is up to temp, will I then adapt the "up to temp mode",

Any advise on the above guys, I'd love to understand if I can possibly self correct this by resetting and driving a certain way at certain temperatures or something?

 

My car started having a similar issue to what you are describing above. Most notably the droning sound. After a lot of diagnosing, we found out that it had the old Valeo radiator which leaks coolant into the transmission fluid. We replaced the radiator with the new BEHR one, flushed the transmission fluid, and put new transmission fluid and it's been perfect since then.

It's either going to be that or the conductor plate on the transmission is going bad and needs replacement.

It's best if you can get the car scanned with STAR to see which fault codes come up. Also, when was the last time transmission fluid was changed?

 

Hey,

I had the same problem earlier in the year, had a leaking Valeo, but caught it early, replaced with BEHR and flushed completely, readapted Lockup clutch and she was good right up until I did the reset procedure,

Hence all my questions concerning the adaptions and the link to the lockup clutch, I'm hoping some of the 722.6 veterans will be able to shed some light on the observations for me.

 

FYI, that "reset procedure" where you press and hold the accelerator pedal and turn the switch, then wait 2 minutes for the "click/ping" sound, well, that does nothing with the TCU. It simple synchronizes the "drive-by-wire" accelerator pedal with the throttle position sensor on the throttle body.

 

Thats exactly what I thought, but immediately after performing that procedure the symptoms started, and performing more resets and driving differently seems to alter when the symptoms appear

I don't believe its just coincidence, there must be more to that procedure than just resync,

Anyone have a WIS article or something concerning the above procedure.

 

A family member just bought a 2004 CLK500. Is there a way to see if it has the Valeo radiator without taking off the whole front end?

 

You should be able to check the radiator visually with nothing more than opening the hood:

http://forums.mercedesclub.org.uk/sh...42&postcount=3

 

TCU reset is done through STAR only, its the only way to access the TCU. The throttle thing that your doing is altering the adaptation of the transmission to you driving style, period. Nothing else changed. The change that your feeling is going to happen for sure because the transmission is shifting at different points and actuation the torque converter (the cause of your jerking and droning) at different times because of the driver specific adaptations. Check for water, if your good then have your TCU reset, if that doesn't solve your problem, you either have a bad torque converter or a bad TCU, or even the Valve that actuates the Torque converter can be broken. All of these issues have specific ways to test for, and all are on STAR.

 

Hey Daniel,

I think you've hit the nail on the head, but this does mean that something is not 100% since the TCU is supposed to re-adapt from your driving after a reset, and my symptoms don't seem to occur frequently with anyone else performing the procedure.

What we going to-do is refresh the box again, and then reset the TCU and re-adapt the Lockup Clutch,

Does this sound like a good plan?

Whats the correct procedure to-do after reseting the driving style adaptions? Drive aggressively, drive with the steptronic? Any advice?

Regards,

Ebrahim

 

Yes sounds perfect, I'd say after a reset drive through the gears consistently, As in take it easy no sudden changes in the pedal and try to drive through the gear in order. The perfect place to do this is on a highway with places to stop on the side of the road. I'd start from 1 and drive through the gears till 5 then slow down again slowly to stop then again a couple times, maybe 10 times. that should be enough. Also i had this occur in my car and i changed out the torque converter for a refurbished unit that didn't solve my problem, then i replaced the Valve that actuates the lockup clutch and still no solution then finally i tested out a different used TCU with the same part number and problem solved, 40$ was all it needed. Though all this was my fault as my trusted close friend and mechanic told me after his testing from the git-go that my TCU was shot.

 

Thanks for the feedback man,

We going to re-adapt on Friday using STAR and reset the TCU, obviously inspecting the TCU for any fluid etc, then we flushing the box completely again(TC included) if not resolved, then we will look at the TCC (PWM)Solenoid on the conductor plate, and maybe the conductor plate itself, after that, I don't know anymore,

Can the Lockup-Clutches be replaced? or maybe block the Lockup Clutch from working like some other guys have done on the 722.6?

 

You don't want to block the lockup clutch from working, I've read about that procedure and its not reliable at all, it will cause all sorts of problems down the road, also a much lower fuel mileage. I've replaced the lockup clutches, they refurbish them and fit new springs, but you'll have to ask around to find somebody reputable to do it. Did you do the gylcol test before going into these things?

 

Ok I'll take your word on the block procedure, as for the glycol test, to be honest I haven't re-tested, since I've already had the issue earlier in the year and replaced the radiator with a BEHR, also the sequence of events has kind of led me to believe its unlikely to be Glycol since the symptoms I experienced happened after resetting the driver adaption values.

The car however now has a constant jerk in 2nd gear around 2000-2800 rpm depending on throttle input, and it seems like the TCC is droning in 3rd when coasting, I can literally hear the droning sound as I coast in 3rd but the sounds pitch is in relation to the deceleration of the car.

If I floor the car, the shift to second happens higher up the RPM range and seems to "bypass" the TCC, its on light/slow driving throttle that its the most noticeable and most violent jerks.

Is it at all possible that after my reset, the TCC adaption got thrown out, as a result, there is accelerated wear on the clutches and now theres extra graphite circulating or blocking the valve body,

Regards,

Ebrahim

 

Yea, annoying as hell. Same symptoms as mine its the TC for sure. Now the issue is figuring out what part of the TC. sounds like it most probably is in need of a good calibration. In my case the problem started out with the TC droning and jerking only on cold starts in the morning, just like you. then about a month or 2 in it got serious and never went away. because of the cold start issue i didn't believe my mechanic when he told me its the TCU, i was pretty sure it was hardware failure because of the hot/cold difference. That mistake is what made me pay 800$+ instead of the 40$ as my mechanic/friend had suggested. Good advice with a problem like this is double check the simple things then move on into more expensive solutions. Don't make the same mistake as me. I had my trans replaced with w almost new but used unit because when I finally had the problem solved I was doing a flush and noticed way too much metal in the oil. Decided to ask around for a transmission and got a great deal on a used 722.6 that had 20,000km on it and its a 2005 model (updated internals).

 

So I found an article concerning the lockup clutch. Which I'm 99% certain is my problem.

But can anyone explain how I do the adaption outlined in the article.

1st Step, adaptation via coolant temperature:
1. Perform cold start
2. Engage gear range "D"
3. Move steering wheel to straight-ahead position and brake vehicle for 20 seconds with service brake
4. Drive until coolant temperature has increased by approx. 20°C (at least 18°C but not more than 22°C)
5. Repeat steps 3 +4 until the operating temperature (coolant temperature) of 80-90 °C is reached.

Read more: http://www.justanswer.com/mercedes/3p4wk-heelo-stan-2003-s55-you-ve-helped-with.html#ixzz3lVIxnz2P

Do I just sit in D with the brake on for 20 seconds at each temp? Do I need to put the car into an adaption mode of sorts before actually performing the steps? Or can I do it right now.

 

I have no idea what i read when i opened that link. Doesn't sound like anything i've read about before!

 

So good news,

It was indeed adaptions, We reset all adaptions using STAR and she now drives like normal,

So just a warning to all those performing the throttle reset procedure, it can sometimes throw your adaption values out and cause all sorts of TCC issues,

Always try adaptions first before doing any other costly procedures :-)

Thanks Guys,

 

Great to see you sorted it out without Breaking the bank!

 

Don't mean to get off the subject but Im having a major issue With my 2007 s550 im getting trans fluid in the radiator i change the radiator and the thermostat.flushed everything out now its back im puzzled and this is really stressing me out if any one could help with some insight please

 

you flushed everything? The trans?

what issue are you having that you are puzzled

 

[QUOTE=gixxerboy;6641138]you flushed everything? The trans?

what issue are you having that you are puzzled[/QUOT
Yes my mechanic did the work he flushed the system but its fluid back in my coolant can't tell if its oil or Trans fluid since my trans fluid is dark didn't want to change it all the way out because i heard with high Mileage 150k it could cause the trans to act up so now im starting to think is it oil coming from the oil cooler idk but its no coolant in the dip stick or its not smoking or nothing so i don't think its a head gasket just a very confusing problem and its not throwing any fault codes

 

I'm guessing (please correct me) that the drone sound is coming from non-oem changes to the exhaust? I don't seem to have this issue....

Just wondering.......

 

reset procedure works ! (c200k 2001 coupe)
1) i have a manual transmission - some of you say that this procedure affects driving style and so on... not its not.
2) i didnot even open air box i did it in a car.
3) proof : when i noticed power loss i checked with obd2 - torque pro. 0-100 kmph 13.6-13.8 after reset 9.2 ( just one try, from 2k rpm and crappy tyres... could be much better ).


but it happened to me after 3 days. today i pushed accelerator and car ran like 1.4 civic witch i sold this month. i stopped repeated procerure and power is back.

now i thinck what to do... i could buy enoter sc throttle but what if its something else ?
if u guys faced the same problem plz tell me what u did ?

 

I have just changed my MAF and now my rpm idle is moving up and down whenever I start my car and almost turns back off sometimes

 

You have a vacuum leak. Most likely created when you replaced your MAF.