China Mobile Secret Codes
Default user code : 1122, 3344, 1234, 5678

Engineer mode : *#110*01#

Factory mode : *#987#

Enable COM port : *#110*01# -> Device -> Set UART -> PS Config -> UART1/115200

Restore factory settings : *#987*99#

LCD contrast : *#369#

Software version : *#800#

Software version : *#900#

Set default language : *#0000# Send

Set English language : *#0044# Send

Set English language (new firmware) : *#001# Send
Sefault user code : 1122, 3344, 1234, 5678
If anyone knows more china mobile codes, pls let me know.