unlock key function :
When you want to use the car key to another car ,you can unlock the key ,make it to blank key .
1 Just remote key can unlock ,smart key can not
2 Just cas1-3+ can unlock key ,others can not
3 Must need to have the original car or car data ,then it can unlcok the key
4 Cannot unlock the only key (the last useful key cannot be unlocked)
Recovry key position function:
If you want to use the key position again(to add new key ),we need to recovery it first (The BMW #1 and #2 never recovery it )
Connect your OBD then click Recovery key bit ,It will recovry your key position to original status ,all FFFF
