ESL's/EZL's how they are used in Mercedes System
Electronic Steering Locks
With the introduction of DAS 3 immobilzer system's came the addition of the ESL. These we're implemented since older blade key versions had a mechanical connection to the steering lock. With DAS 3, it was the first Infared Key in the market and had to use an electric style lock in place of the older mechanical version.
They were connected to the EIS ( Electronic Ignition Switch) Via a 1 wire K-line data bus. As the key was inserted into the ignition, the EIS would verify the data and send a release command to the ESL ( Electronic Steering Lock ). Once the ESL received the data, it was then cross referenced whether it matched the stored key information within. If it all matched up, the lock would be released and a message would be sent back to the EIS to start the car.
Over the years the the level of encrption has been increased, making it harder for these parts to be replaced or renewed with used ones. With the Diagspeed tool you are now able to renew the ESL and program it to the vehicle. Mercedes has made getting access to TRP parts ( Theft Related Parts ) harder and more complicated. With the Diagspeed, you can skip the Dealer completely and have the ability to renew ,replace and program ESL's within minutes.
Currently the W204 W207 W212 W172 chassis version ESL's have been having common failures of the locks and has opened the door for repair shops/ locksmiths to capture that business. If you have access to order these parts from the dealer, it usually requires the purchase of a Green Key or an Orange key to program the lock to the car and a 2-3 day wait time to receive the part. It has been a common practice to have rebuilt ESL's or even using an Emulated version of the ESL. This saves time and money for everyone.
New software releases have now allowed the function of renewing and programming ESL's for W245 W169 chassi versions. The first and only tool to provide this function.
This is another reason why most people consider the Diagspeed as the BEST Mercedes tool on the market today.