How-to: repair Mercedes W211 original EIS rolling code with CGDI Prog MB Key Programmer.

Rolling code :

A rolling code (or sometimes called a hopping code) is used in keyless entry systems to prevent replay attacks, where an eavesdropper records the transmission and replays it at a later time to cause the receiver to ‘unlock’. Such systems are typical in garage door openers and keyless car entry systems.

Why need repair W211 rolling code?

Most of keys are too fast to be inserted and removed,  the track code does not roll, resulting in code rolling, so the key and the EIS cannot be matched properly. CGDI MB has the ability to repair Mercedes rolling code.

Tools required:
CGDI Prog MB
Analog key data collector
OBD connector
USB cable

Follow main steps below:

1. First you need a key password
2. Calculate the track code of the key
3. Read the EIS, fill in password and save data
4. Calculate the erase password and erase it
5. Load the EIS data with the password
6. Click “Allow modification of data”
7. Change the track code of the key position to the track
code of the key.
8. Write data
9. Learn key

Step-by-step procedure:

1. Read key password. If there is no key,you can calculate the password by doing all keys lost

Calculate password

2.Calculate the track code of the key. Press Read Key/Chip and read current key information

Fill in the password

Click to get the track code

Confirm that the key has been inserted into the CGDI MB and check that the key password is correct.

The track code calculated by the wrong password is invalid.

Calculate key track code success

3.Read EIS, enter password and save data

4.Calculate the erase password ad erase the EIS.

Press Wipe the EIS to erase EIS

Insert the CGDI Prog IR adapter into the EIS within 30 seconds.

Erase EIS success

Read EIS and check current status

The EIS is erased

5. Press Load EIS data to load  saved data previously with key password

View the key position (key position is 1) and copy the track code

Click on Allow data modification

7.Modify the track code of the key position to the track code of the key

8.Write the EIS data

Recommend to write the VIN first, then write the EIS data

Insert the IR adapter into the EIS within 30 seconds

Write EIS data successfully

Read EIS data to check current key status

Insert the original car key into EIS to learn key, the EIS can be activated

Insert the key, wait 1-5 seconds, the ELV responds,  the EIS is activated and the key learnt successfully

Read EIS data again

W211 EIS original rolling code is repaired by MB Key Programmer CGDI MB successfully.

Done.