Please after changing the battery of my VOLVO v40 1999 wagon car the radio requested code can you help me

This is a anti-theft device built into your radio designed to foil robbers. When the radio looses power, the radio locks up. This makes the radio worthless on the black market. The thieves know this and don't steal it as a result. Your owners manual tells you to clear the code if there will be a power loss (changing the battery). There may not be a recovery procedure.

In the GM (1995) version of this system, there is no recovery (if there were, what would be the point of the system?). I don't know the specifics of the Volvo system. You may want to talk to your dealer before you replace your radio. I am sure you will have to prove ownership of the vehicle.

Thanks for your question @ FixYa.com this morning.