ninsei

Hi. I have a 2007 CLK 550. Does anyone know the latest version of the stock TCU software is for that?

daking1959

I have seen posts about firmware upgrade forTCU from the dealer. My 09 CLK has 17k on the clock. and shifts very smooth. I rarely use the paddles or touchshift. If your transmission is jerky, then this might be something to consider. Im interested to see the replys. KeyHole, and Rudney, are great at this stuff.
regards
dk


PS Gonna call the dealer on Monday, to see what a flash to my TCU will cost, and what it actually does.

Rudeney

Only the dealer can flash new OEM TCU code. I don't even know if there is a way in SDS to tell what version is flashed.

ninsei

K. just went to the dealer and they said there is no software update for my car (it's a 2007 CLK 550). He put my VIN in his computer before he said that.

Rudeney

That means one of two things. Either (a) the update was already done on your transmission or (b) the tech did not actually check correctly. I was actually not aware that they could tell by VIN, but I do know SDS has to have the VIN and a live connection to MBZ to get a download, so I guess it is possible.

ninsei

hmm, maybe he just checked for any open service bullitens for my car.

Rudeney

That's a possibility. There is definitely at least one TCU update for the 722.9. It smooths the 1-2 and 2-3 upshifts, plus it keeps the 2-1 downshift from occurring until the car has stopped (which helps with a seemingly harsh or clunky downshift when slowing). It made a huge difference on mine.

ninsei

thanks.

i went back to the dealer again. they now understood what i was asking. they said: if i dont have any problems, dont do the update. since i like the way it currently shifts, i walked out of there without doing it. im pretty sure i have the old software since it does, sometimes, downshift to first.

mguerrero

can someone explain this to me?? whats the issue that causes a need for a TCU update? what models is it for? Thx

Rudeney

Your CLK55's 722.6 should be fine, but the 722.9 with its 7 gears has a different program and sometimes it can cause harsh shifts or unexpected up/down shifts. As customer complaints were registered, the engineers adjusted the program to make shifts smoother. For example, a downshift to 1st gear while rolling could create a thunk or thud, so the software was changed to keep the car from downshifting to 1st until it was topped and the torque converter lockup was disengaged.

Tzvikramer

Do dealers normally charge for software updates to the TCU? How much would they run?

ItalianJoe1

For a car that's out of warranty, yes it's charged like any other repair. An hour minimum would be standard.

Why do you want it updated, just for fun? If you're having actual issues, software updates probably aren't going to fix it at this point.

Tzvikramer

It's having the slow, jerky shifting described above. I can't tell if its the software, needs new fluid (changed every 40k), camshaft magnet (code P0025 popped up and went away after reading it), or the intake manifold flap (code comes up on shop reader as stuck in open position. But no check engine or major problems.)

ItalianJoe1

Software doesn't go bad, so if it's always done it, then sure try the update. If it's a problem now that you've not had since new, odds are it's mechanical. Fluid is very important in these transmissions, so if you haven't serviced it in a long time, try that first.

Tzvikramer

Thanks,

Its been like this ever since i bought the car in January. Up until yesterday it had 5w-30 synthetic but switched it to the 0w-40 with the fleece filter. SEEMS like it got a little better but I still get the jerk when slowing down sometimes.

ItalianJoe1

Engine oil won't affect it...

Start with a trans service. If you only have a couple months history with it, that doesn't help. Maybe the old owner got rid of it because it was shifting bad and they told him to rebuild the transmission.