There are no shadows by default in DS, you have to turn them on in the lighting Parameters pane for each light you are using. If you are not using added lights, then shadows is not your problem, it may be a parameter of pwToon that is set in a way that you don’t want..
Can you post an image of what it is you are seeing?
Here it is. Now I know throwing in lights will be the only way to truly brighten the image up, however, I am looking at just having the basic option to post work shadowing or just have a clean image without shadows. As you see the floor in the first image is all blacked out. The panel in the second one on the floor, centered, is black despite having a panel like the ones in front of the seat. I know what you mean about having no shadow by default as I have rendered ones clean and everything shows up fine, albeit dim.
Click thumbnail to see full-size image