drs253

Hi all - I recently purchased a 06 ML350 with approximately 23k miles. I'm having a 'problem' with the transmission I'm hoping someone can help me out with.

While gently accelerating from a roll (think 10-15 MPH traffic), the transmission will up-shift almost immediately. This drops the RPM down to 1100 and most of the time requires an almost immediate down shift, especially when then needing to accelerate quicker. This problem is also very evident while turning. Going into the turn, the transmission holds a lower gear (IMO like it should), but then accelerating out of the turn the car immediately up shifts.

Anyone have a similar problem? This makes for a very jerky ride since the transmission is constantly shifting gears (especially in traffic).

Thanks,
DS

sosh

This has nothing to do with the valve body replacement. Could be one of several things. First, its an adaptive transmission that learns your driving habits. you have no way of telling how the last owner drove. Continue to drive it and try to be aggressive. that may change the shift points in time. second have a dealer check for what version of software you have if its been superceeded have them reflash it with the latest version. Its also been my experience that most all automatic transmissions behave the way you describe to a certain extent.

tmerhebi

Exactly the same problem..

Changed valve body and TCU.. problem still there
changed torque converter.. problem still there
changed Air MAF... cant resolve car is sitting at dealer been 2 weeks now.. please help anyone.. what could it be???? willing to try anything i have a 2004 SL500 with 7g tronic

drs253

My car is at the dealer now. I took a tech out on a drive and he insists it is normal due to the AWD. I don't buy it. He's going to take it out in stop-and-go traffic today to see if he sees anything abnormal. But he insists (and we had a long 20-30 minute conversation) that they all do that.

tmerhebi

it can't be because of awd because my SL500 is a rear wheel drive and its driving me nuts since dealer can't find any faults... please update me when u have news.. thaught it was torque converter its not...

Tomorrow dealer is going to update ECU software and do the adaptation for torque which he didnt do yet. I hope it fixes.. will update you asap

tmerhebi

By the way do you also feel the loss of power directly after the upshifting when gently accelerating from a roll. (A second later it becomes more responsive again but do you feel this second where theres almost no power or no response after the upshift??)


Latest News: 90% fixed don't know if its completely fixed or not I will update you after driving it for a few days but took it for 30 mins while at the dealer upshift directly after acceleration is GONE. waiting a few days to confirm..

Tell your dealer to re-adapt the torque converter
its called torque converter lockup adaptation procedure done with the STAR system.

its 90% better still some tiny hesitation willdrive for a FEW days to confirm if it has fixed the problem..

Regards and please update me on ur situation

drs253

Thanks for the suggestion. It couldn't have come at a better time. The dealership called yesterday and left me a message to come get the car and there wasn't anything they could do. Just as I was about to leave to go get it, I saw your post above. The service advisor hadn't heard of the procedure, but he was going to pass it on to the shop foreman. I'll keep you posted.

Thanks again.

DS

tmerhebi

90% fixed only problem left is hesitation tranny or engine hesitates after pressing on gas pedal.. looks like its in a high gear (number) and takes time to accelerate..

No clue on what to do next.. waiting for ur feedback.. heard might be the fuel pump so u could also ask dealer to check urs out

drs253

Got the car back. They didn't do the torque converter procedure because they said that was only for a harsh 2-1 down shift. They applied the latest computer patches that just came out within the last couple weeks. That seems to have fixed it. I'm much happier now, although it has only been a couple days. I'll keep you posted if it changes down the road.