Your best choice for all information you will need is the factory service manual. (it's parts, diagnostics, service procedures, schedules, specifications, wiring diagrams, everything you need to fix your car.)
It's called VIDA. You can purchase a subscription from volvo @ volvotechinfo.com. OR
You can easily find free on the internet - the stolen and hacked VIDA 2014d. That is info for up to 2015 year model cars and came on a double sided DVD. If you want to plug in and read codes and stuff -(everybody does) you will need a dice unit. The factory dice unit will be needed to download new software (you won't need to do that) or you can buy a clone. I spent $85 on a clone a few years ago. You will need a win 7pro CPU to install the software on - but any other "service/repair manual" is a waste of time. Others have win10 solutions or sell memory sticks with vida preinstalled also.
