When I put my key in the ignition of my 2008 dodge grand caravan, it reads badkey & wont start. what is the problem?

Newer Dodge Vehicles do not have an ignition for a "metal" key. They use the Electronic Key called a FOB with a built in or integrated metal key that is only used to unlock the door. The FOB inserts into a WIN module (Wireless Ignition Module) instead of the normal igition. Reprogramming the vehicle usually does the trick however there has been significant problems with the WIN module and the dealer may have to replace it. The 2010's have a recall on some models. The manual states the keys cannot be reprogrammed. The first and easiest solution might be to try replacing the battery in the FOB (aka key),

You have a computer chip in your key, you can't use keys made from the local hardware store, it must be a factory key. Assuming you have a factory key, try one of your other keys, if none of them work, and the car is under warranty(or even if it's not) call your dealer explain the problem and they will likely have it towed. If none of your keys work, the cars computer is not working properly and needs to be reprogrammed or replaced, if any of your other keys work, then it is probably the key itself.