Does this work on CLK's?
 

FOUND THIS ON A C32 WEBSITE, Nick

Purging the bad data



When the factory designed the software for the engine and transmission
mapping, it was obviously based on the hardware parts being completely broken
in. Yet our car's computer has been building up a "learned" database during
breakin, when the parts are wearing in to their "set." Thus, there may be
incorrect relationships between what the engine and transmission are doing
compared with the design. The factory says it takes at least a 1000 miles to
breakin, but I have waited for 2000 miles to pass before purging the bad
data. The time has arrived to reboot the operating system, just like Windows.
It is quite a simple process. Just disconnect the battery for about 30
minutes. 30 minutes is a good amount of time to be sure that whatever can be
purged, will be purged. After reconnecting the battery, and performing the
four "sync" operations in the handbook and resetting the "settings" and time,
everything is back to normal. Drive around for a few miles, and the good data
will have been learned.
My results are fantastic. The transmission shifts are now perfectly torque
managed the way AMG designed them (eliminating the abruptness I had on
1st-2nd at about 3000rpm). The occasional delay in locking up the torque
converter in 2nd and 3rd gear is gone (sounded like slipping the clutch on a
manual transmission). The engine idle is smoother (it sounded a little lumpy
before). The throttle response is sharp (feels like another 5 hp has come
out). I have done this purging, i.e., temporary battery disconnect, on my
last 10 new cars. For some, the results were dramatic (like this C32), and in
others, hardly anything was different. It probably depends on the individual
car. A mechanic told me about this trick back when on-board- diagnostics
(OBDII) started getting complex in the mid 90s.

Probably the main benefit is that you'll erase the data collected by the adaptive transmission. Of course if you take it easy during break-in like you're supposed to, it'll think you always want to drive soft, so it won't react the way you may want when you start driving it hard.

I think the main problem is that most people baby their cars most of the time, and drive them hard only on occasion, so the transmission is just going to relearn the bad behavior.

I wonder if it affects the ECU data. I know some cars do collect data dynamically in the ECU and disconnecting the battery forces them to relearn how to run, which means they run like crap for a couple minutes after the battery has been disconnected for a while.

The computer is constantly adapting. If you were to drive the car hard for a little bit, you'd get the same results.