Upload & Sell: On
Make sure that the contacts on both ends, the lens and body, are cleaned. It won't hurt to use the old trick of cleaning the lens' contacts using a soft pencil eraser. You will never know, it might work after that . If it still acts up, I would send it in to Canon and get it fixed. You can sell it for more after the repair than the way it is. I wouldn't let the lens end up as an expensive paperweight.