When I bought the CarSoft system, they strongly recommended not to use an USB to serial, (RS232), adapter, it could cause bogus results in both reading an error and sending a command, (as in erasing an error). This could be a key issue. You must use a native built in serial port or a PCMCIA to serial port adapter card, as you can see in the pic attached.
I suggest you to run all the tests again with the proper serial interface and pull all the errors and conditions found. There is an abridged version of the manual in the welcome screen of the software, it is a kind of help screen. There are instructions with plenty of photos on how to connect the cables in both the pc and the car diag connector. You must use the 38 pin connector if you have the multiplexer. You don't need to use the banana plugs. The box I have has 3 connectors and three dual color ]LED'S, (see pics attached), on one side there is a 37 pin male connector, you must connect there the 38 pin diag cable that hs a female 37 pin on the other side. On the opposite side of the box there is a 9 pin female connector that you should use to connect a straight serial cable to your computer serial port, (NOT TO AN USB/SERIAL EMULATOR). In addition on this same side there are three LEDs: Power, MCU and K, along with a round connector with 3 pins that you will not use for your 600. You can check the handshake process sequence with the LEDs activity.
Follow the test procedure as stated in the manual, or in the software initial screen, and I am sure you will find out what errors are active or stored as well as what modules might have communication problems, not respond or does not exist. If you find some errors in the complete test, you must run the specific module test in order to pinpoint the cause. Some times one condition triggers several errors in different modules and other times some errors in one module hide errors in others. So an individual module check is highly recommended. This is a very important differentiation between CarSoft and DAS STAR.
CarSoft is relatively simple and easy to use, if you don´t mess around with the special functions like the adaptation erase, you should not make any harm to your car while using it, unless as mentioned before it is receiving and sending bogus info from and to the CAN in the car.
Pics are from a w202, but for illustration and verification purposes are useful.
Along with the LED's blinking before and during a test, there are some relay noises from the CS box.
Hope this would help, if need some more info or elaboration on a specific task, please let me know, I will try to help.