It would help if you would actually post the ECU and car.

Otherwise:
Yes.

Search for CW_CAN_S in FR, it will show which messages are under what bit, you can check if they are enabled, and right after it are the descriptions with the formats of all the messages.
Motor 1 should always be on.

Can bytes are the simply memory adresses in iram tipycally in 0xF8xx area
Look in FR-CAN, there is a 0x280 msg and you see there is nmot_w goes to byte 3 and 4 as a word
The easiest tracking way in that case is to find pretty rare used variable near yours
So there is also mifab_w going to byte 5 as i said this var used only about 10 times in flash (x for crosslinks)
Jump on those crosslinks and search for something like

mov r4, mifab_w
shr, #8
movb 0F826, rl4

so this 0xF826 is 0x280 byte 5
and right above should be the similar routine with 0xF825 and 0xF824 for a byte 4 and 3 with nmot_w goes in it