slk shifting problem
 

Having problem with the shifting of my 2000 slk 230. Automatic transmission does not shift up sometimes after I have applied hard braking or after I have made a tight turn at low speeds. This does not occur all the time. I can normally get it back to normal operation by shifting into neutral and then back into drive. When this doesn't work I have to pull over, stop, put car in park, shut off the ignition and restart the car. My question is based on this problem description, is it some kind of electrical/switch problem or an internal transmission problem.

there are a few parameters to precheck before you can proceed to any repair.

1 - how old is the ATF (what ATF is in there)
2 - level of ATF good?
3 - is the electrics connector dry? (if oily then check for ATF in the TCU case)

If all is ok - then get a deep level scan that can interrogate the TCU on MB - some errors will pop up - note them and then proceed. If you see a failure to shift or speed sensor error then you need to replace the electrics plate in the transmission valve body.

Yeah let's start with ATF before any conclusions.

I still see a few of these cars with original fluid because they are "sealed for life" people still claim every now and then.

Check the level. Your car does not have a dip stick. It has the port, but you need a testing dipstick

Mercedes Benz 722 6 Automatic Transmission Fluid Dipstick MB 140 589 15 21 00 | eBay

Radiator level okay? not contaminated?

Get the dipstick..

Martin