Nah no checksum needed in tp5, there's a box thats ticked for 2's complimented for checksum what ever that does must fix it when sending the command!
With tuning the VY, you need to know what calibration it is & then use the correct XDF & can tune anything from trans pressure's timing's, eng rpm limit, timing, AFR list goes on & depends on what has been added to the XDF, but really think you need a new thread for that!
My best guess is you calibration will be 92118883 which I think is $06b!
Need to start getting a list of commands & devices & the likes for this thread though!