diagnostic code 2002u macro pro 2010

If you are trying to boot the Apple Diagnostics or Internet Recovery Mode, then it means you have some sort of network issue. Try connecting the laptop directly to the router using an Ethernet cable for a faster more reliable connection which also bypasses any possible WiFi issues. You can also try rebooting the router (wait at least 5 minutes for the router to finish booting).

Also try a PRAM Reset (hold the PRAM Reset for at least three chimes).