Pues a raíz de ver un post, he investigado y he encontrado estos códigos secretos (parece ser que son genéricos de HTC:
HTC specific codes
*#*#4636#*#* = device information program
*#*#7262626#*#* = Field-Test
*#*#3424#*#* = HTC Function Test program (very useful!)
*#*#1111#*#* = Show software version
*#*#2222#*#* = Show hardware version
*#*#232338#*#* = Show WiFi mac address
*#*#232337#*# = Show Bluetooth mac address
*#*#1472365#*#* = GPS test
*#*#1575#*#* = GPS test #2
*#*#232331#*#* = Bluetooth test
*#*#0*#*#* = display test (?)
*#*#2663#*#* = touch screen version (?)
*#*#2664#*#* = touch screen test(?)
*#*#759#*#* = Rlz Debug UI (?)
Sacados de aquí
http://forum.xda-developers.com/show...php?p=26796980