2012 Dodge Grand Caravan work fine yesterday today not starting it asking for the security code onthe radio would that keep it from starting?

Some gm models have a feature where if something is wrong with the radio the car wont start. It is amazingly stupid which is one of many reasons why foreign cars are so popular in the united states. You might have to hit up the dealership for the security code.

So the radio told you that ,right.

Battery died. They can go overnight once the cold weather moves in.

The owner's manual is your friend, which wants very bad;y to help you with this. Oh, if you would only get it and read it a little.

When originally purchased the security code should have been issued and noted in the operational instruction book. Everything in the car worked except the radio. Recently I had a similar problem after I charged the battery in my 1999 MB. I contacted the dealer and identified the last 4 digits of the VIN #. I inserted it on the radio window when prompted and the problem was fixed. Good luck.

Replace the battery if it's more than 4 years old.

The security code thing more likely relates to your Bluetooth settings. Your iPhone wants to pair with the stereo.

The battery is dead.