I KNOW this is a very popular subject. This is for you guys that KNOW your 4 digit code but have disconnected the battery and can't get the letters CODE to come up on the display screen in the car! In my case all I was getting was OFF and a blank screen. If that is YOUR case, here is exactly what you do to fix it. 1. Turn ignition key to Accessory and push radio ON/Off button to where the display screen on the dash is blank. (It should go from reading OFF to blank). Leave on accessory for at least an hour. 2. After one hour has passed push in the radio's on/off button and the MEMORY #5 button on radio simultaneously.At this time the word CODE should come up on the display. 3. Input your vehicle's 4 digit code using the first 4 memory buttons on the radio.First memory button for first code number, second memory button for second code number and so on until all 4 numbers have been input and are displayed on the screen. 4. Push the CD button on the radio. A beep sound should be heard and your radio/CD player will work again!