WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
Ignition off. Disconnect the battery negative lead
Fig 1: Identifying Ignition In Off Position And Disconnecting Negative Cable From Battery
Courtesy of VOLVO CARS OF NORTH AMERICA.
Check that the customer has provided the radio code.