How do I register the radio in my Citroen ZX,I have the code No. which works but when I switch either
the car or the radio off it goes straight to' cod'. when the radio is running it only runs for a few minutes with a five second 'beep'. The radio does not have a cassette player, therefore no 4way control knob. -HELP !.

Bomarbob, October 2013

No computer or OBD port on these cars.

Gary, February 2014

I recently had this very same issue. You must enter the CORRECT radio code using 1,2,3,4, buttons and then register the code, using the left tune button. It's the one with two arrows. You can enter any random number and finish by pressing the "5" button, the radio will come on and work but beeps and then turns off after a few minutes.
I hope this helps people in the future.

Gary, February 2014

it will need to go onto the correct computer to code in your radio.

cdc, October 2013