aeroman

So I know that some AMGs (my E63 did) will keep RPMs high and the transmission in a lower gear if it thinks you are driving aggressively. Since I had my ECU reprogrammed with later version of software my SL65 hangs like this forcing me to use the paddle shifter to upshift and get the RPMs down.

For example...... Yesterday on way home I actually found some open freeway so a went WOT from about 65 MPH to 90 then let off to idle. The car stayed at about 5000 RPM and in the same gear until I upshifted with paddle shifter to 5th.

If you wait and let the car do the upshift it generally lets go like it doesn't want to and the rear end bangs.

Hopefully that all makes sense to someone.

Thoughts?

dRockSL55

I believe this behavior is due to amg "speedshift" tcu programming and is considered normal operation. I have noticed similar upshift hangs on my sl55 following wot bursts. I've found that the tcu will upshift the trans smooth and quick by just slightly easing into the accelerator for a second instead of full idle on the decel - otherwise it will hang for a bit with aggressive engine braking before a firm upshift or downshift depending in how much speed was lost.
Another way to avoid it is backing off the throttle more smoothly rather than abruptly letting off.