Reading The Control Module ID
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.
The Volvo Scan Tool (ST) identifies control modules by reading a code from the control module memory. The code contains information on the part number of the control module and the software version it is using.