https://cimg2.ibsrv.net/gimg/volvoforums.com-vbulletin/1300x867/642a1920_a8b2ee3857addb5d632a48ba94f4bc5cd781692e.jpg

Here is an ECU engine control unit for XC90. In order to get the CAN traffic from it, you firstly need to find out the CAN pinout.

https://cimg0.ibsrv.net/gimg/volvoforums.com ...

At quick glance you have PSM listed twice.
-- they mapped two different CAN IDs. Volvo uses either standard or extended ID.

sniff CAN Bus traffic from OBD port and do a little research on the CAN frames.
Here is some findings:

Volvo has heavy CAN traffic, 2400+ in less 2s.

https://cimg0.ibsrv.net/gimg/volvoforums.com-vbulletin/1300x584/volvo1_01154b08af129c1e17322f788fbb85eca4d5b109.jpg

statistic information ...

Volvo odometer/mileage is stored in multiple ECUs: the instrument cluster(Drivers information module, DIM),
PSCM (Power Steering Control Module), ABS, TCM(Transmission Control Module）or VDDM(Vehicle Dynamic Domain Host)。

Furthermore, volvo also broadcasts odometer in its CAN messages,
e.g. CAN ID ...

ABS/BCM Anti lock brake module
ECM Gasoline engine module
TCM Automatic transmission control module
DEM Differential electronic module
SAS Steering wheel angle sensor module
HCM Headlamp control module
VCM Vehicle wiring module
TELM Telematic
IHU Infotainment host
TVM TV module
AGU Additional ...