Locate reset button on Kenwood ddx512 - Kenwood Car Audio & Video

I would try gargling it; type "
Kenwood ddx512 manual" into google

http://www.tech-faq.com/how-to-reset-a-kenwood-security-code.html

Maybe need to reset it. Would also talk to Kenwood.

protect mode on kenwood DDX512 is due to a burned out the output amp.,or in last case the tuner bloc is damaged. try checking first the amp. ic.

1. Check the fuse at the radio and in the vehicles fuse box
2. Check the wiring of the radio to ensure nothing has come loose/disconnected
3. Remove the radio and test it on another power source to ensure it is working properly.

If it's not the fuse (Step 1) I recommend visiting a quality local Car Audio specialist and getting them to assist you.

If you have the manual check for it in there. If not listed then I would call Kenwood to see if they will help you over the phone which shouldn't be a problem.

I had the same problem. Updating the firmware for the Kenwood resolved it.

Try checking all of your connections something may have come loose, usually its a speaker connection that may have come loose and come in contact with a piece of the car's chassis or a metal part. This will cause the 512 to go into Protect mode. When you fix this hit the reset button.

my kenwood DDX512 IS LOCK I NEED A CODE TO UNLOCK IT

you must call Kenwood tech support, the code will need to be reset