I have a 2002 C240 automatic with close to 100K miles. Yesterday I was in a rush and started the car and put it in reverse quickly. The car died. It seems to be a problem with the computer &/or electric.

The dash board display changes what it shows. It has said various things, like "visit workshop”, something about the DTR, even shows stuff like “178o+” or something for outside temperature. The dome light works intermittently and the door locks work with key sporadically.

I checked all the fuses they seem to be okay. The battery was low, and I charged it but that doesn’t start the car. I read somewhere about unconnecting the negative post of the battery, waiting and then reconnecting, but that didn't work. This morning when I went to try to start it again, the alarm went off and I had a hard time shutting it off. I only have one key so I can’t test another key.

What could be the problem? Is my only option to have it hooked up for diagnosis? greatly appreciate all help, ideas!