When using the Mercedes-Benz device to read and write Xhorse mercedes smart key, you will find an option to read the 0CF4 key.
So what is this option for, and what form of key it reads?

Usually, the Mercedes-Benz key (activated) we use normally only has the HASH tooth track of one key, and we cannot see the relevant data and key codes of the other 7 keys of the car, but the 0CF4 key is a special existence.
Before being activated, this key can read the HASH, SSID and password of the 8 keys of this car from the key information.
If you insert this key into the inactivated blank lock head, you can write all the data into the lock head and activate it.

When the lock head and the key are activated, the key can only read the key information at the current position, other key information and passwords will also not be read.

Usually, the BGA key cannot directly obtain the password from the key, that is, the second-hand BGA key cannot be reused at this stage, so what' s the practical use of Xhorse mercedes smart key 0CF4 key have for us?

Some BGA-type smart keys currently on the market are unstable because of the existence of some sub-factory keys, and some customers who need the original BGA smart key can use the 0CF4 key for matching.

Since the password and related anti-theft information can be read directly from the 0CF4 key, these information can be written back into the EIS lock head, meanwhile, the SSID and HASH in the anti-theft-related components such as the engine, gearbox, and gear lever should also be synchronized, so that the 0CF4 key can be used normally.
However, although this method of operation can obtain the original key, but the original anti-theft information of the vehicle has been changed, it is usually used as a research test.

The Xhorse mercedes smart key OCF4 key is only a knowledge point that everyone understands at work, and the practical use is not very great.