If you are in need of Mercedes replacement key programming, look no further – BOTR Auto Locksmith Ltd can certainly help. If you’re interested in seeing how it is done, keep reading.

When programming a key to a Mercedes vehicle when all keys are lost, the most time consuming part is always calculating the password. This is only a problem in ‘all keys lost’ scenarios, however, since an existing key has the password built in.

Whenever I encounter an all keys lost scenario, I remove the EIS (Electronic Ignition Switch). Extracting the password from the EIS ‘on-bench’ is far quicker than trying to extract it whilst its still hooked up to the vehicle since it allows us to bypass any secure gateways.

The first step in Mercedes replacement key programming is identifying the internal factory chassis code of the EIS. Today, I’m working on a W169. The ‘169’ part of the 10 digit code you see below is the chassis code.

My next step was to get my connection diagrams up. There are a series of devices that you have to connect up to one another before any programming can begin.

Once the wires are connected, you then have to connect up your programmers. There are 3 separate programmers that have to used in conjunction for this procedure. Once connected, it all looks like this.

Step 1 of programming is to read EIS data.

Step 2 is to detect the new key.

Step 3 is to obtain the password. Like I mentioned before, Mercedes password calculation can be an extremely long process; it can take up to several hours!

Once I have successfully extracted the password of the EIS, the programmer makes me a key file and writes it onto the blank key.

Key programming is now complete. It is always good practice to make sure the key has the correct data uploaded to it after programming. This way, we know it is correctly assigned to the vehicle.

All that was left to do was fit the EIS back to the vehicle and test the key.

If you’re looking for an auto locksmith near you that covers Mercedes keys, BOTR Auto Locksmith Ltd operates in Surrey and parts of Berkshire and Hampshire. Feel free to get in touch now!

I hope this blog post was interesting and educational; if you would like to learn more about various key programming procedures, click here. Thanks for reading!