Welcome to Just Answer.
Was the system original with your car or was after market?
Sorry for the delays. I have two questions for you. Did you set the original code for the radio?
According to the manufacturer, it is very difficult to reset the code because of the nature of the security of the radio. I can suggest few things that you can try :- One, You can try a generic Kenwood reset procedure to see if you can change the code:-
1-During the code request mode, while holding the DISP key depressed, press and hold the Volume UP or DOWN key for 3 seconds (so that “…” disappears).Then using your remote enter your code.2-Press the "Auto" button and "Track up" on face of radio at the same time. The four dash lines ( . . . . ) should "disappear".Then using your remote enter your code.3-for Model# ***** and DPX-4030Press and hold the 1 then the 6 preset key (preset keys are the buttons on face of radio for storing you "favorite" radio stations). "C" should display.Then using your remote, enter your code.Enter your number from the remote control unit. suppose Your code number is ***** (KCAR)* Press numeric key “5” ( 2 times ) and press the Track UP/Next Track key* Press numeric key “2” ( 3 times ) and press the Track UP/Next Track key* Press numeric key “2” ( 1 time ) and press the Track UP/Next Track key* Press numeric key “7” ( 2 times ) and press the Track UP/Next Track keyThe security is canceled and the set enters the TUNER mode!
If this was original with a car, there is a code the you can retrieve from the radio that the car dealer can use to process the code. But this is not the case here.
I sorry, I cannot supply you with the 4 digit number as I cannot physically change it for you here online. All I can do is to give you suggestions of what you an try to reset. Have you tried to follow the instructions above?
Link for the manual
Ok, your next option is to contact the manufacturer to get help reset the radio, you will have to show the proof of purchase of the vehicle before they will help with reset.Where are you located?
Do you have the remote for this?
You will not be charged unless you are satisfied with the service. I will opt out and let other experts try this.