The W / S switch is Winter / Summer ( or named something similar ) . In summer mode the car starts out in 1st gear , in winter it starts out in 2nd gear to reduce wheel spin. Reverse in winter is a steeper ratio also to reduce wheel spin.

Be sure to scan the car for codes / look at trans data and don't randomly change parts. With a scan tool you will be able to see shifter position.

It is very common for this trans to have a failed conductor plate ( the speed sensors fail ) It is also common for the trans electrical connector to leak and the oil wick up to the trans computer. The fix is a ~ $10 part and cleaning the trans controller with electronic cleaner.

My 97 E320 parts car is in limp most of the time. What is strange is when this occurs, the high beam indicator is on, fog lights are on and a message on the instrument cluster that I don't remember. One time it worked just fine and the lights were out.

Someone else on this board had a similar problem but never posted a fix.