List of China Mobiles Secret Codes

default user code: *1122#, *3344#, *1234#, *5678#
Engineer mode: *#110*01#
Factory mode: *#987# 
Restore factory settings: *#987*99#
LCD contrast: *#369#
software version: *#800#
software version: *#900#
Show Software Version: *#8375#
A2DP ACP Mode CONFIRMED: *#1234#
A2DP INT Mode CONFIRMED: *#1234#
To Enable COM Port: *#110*01# -> Device -> Set UART -> PS Config -> UART1/115200

Codes to Change Screen Language:

Set Default Language: *#0000# + Send

Set Language to Russian: *#0007# + Send
Set Language to French:  *#0033# + Send     

Set Language to Spanish: *#0034# + Send
Set Language to Italian:   *#0039# + Send
Set Language to English:    *#0044# + Send     

Set Language to German: *#0049# + Send
Set Language to Thai:     *#0066# + Send
Set Language to Vietnamese:     *#0084# + Send 

Set Language to Arabic:     *#0966# + Send