It is all in the part B document in post#4

Your legend for the W210 is on Page 20. Study the two attachments. The transmission oil thermistor(oil temperature) sensor has a legend in the service manual to show how much resistance per temperature. Use your dash temperature reading to give you an idea(on a cold engine)

Many voltmeters measure frequency-even the cheap ones. The modulating pressure solenoid oscillates between 1-2kilo-Hertz. This solenoid feeds oil to the valve body-This solenoid is very important it is working. In simple terms, it regulates oil!! Obviously the the speed sensors can be tested with a frequency monitor.

The solenoids are all 12v(11v-14v).

I know this frustrating, but this is day-in and day-out troubleshooting..

Best of luck,

Martin