You insert the key into the ignition, but your Mercedes-Benz won’t start or crank. You notice that in the instrument cluster you get the message “Computing Data Please Wait” and the key symbol as shown in the picture above. The reason this happens is either because you are using a new key or one of the components of Drive Authorisation System (DAS) is defective. If the key is new then the solution may be simple. If any of the components such as EIS, ECU or EWM is defective that’s another story.
You could use an OBD II scanner such as the MB SD Star Diagnostic used by the dealers or the Carsoft 7.4 Multiplexer which has a reasonable price tag; to read, erase the codes and program the modules on your Mercedes-Benz.
In this particular S-Class our scanner was showing the following error message:
“B1016” NO ENABLE FROM CONTROL MODULE EWM ELECTRONIC SELECTOR LEVER MODULE
This code points to an issue with the gear shifter module. Reading the codes from EWM, we noted the following code.
- Connect a car charger to the main battery. You need a charger that you can plug into the power outlet and can generate at least 10 amperes. A 2 amp or battery tender will not be enough, and the battery will drain too quick. A good choice would be the Schumacher Speed Charger.
- Insert the key into the ignition and turn to position two. All dash lights should turn on. If the key doesn’t turn you may need to use Star Diagnostic Scanner to unlock Drive Authorization System. If you remove the key from the ignition during this time you have to start over.
- Leave the key in the ignition for at least 6 hours for the key to synchronize. We are not kidding. Once the key is synchronized you should no longer see “Computing Data Please Wait” message in the instrument cluster but now you should see the mileage.
This tip worked on our S-Class W220. It took about five and a half ours for the key to pair up with the car. Mercedes-Benz keys come pre-programmed when you order them from the dealer and normally you don’t have to follow this procedure. For us, this wasn’t the case and we were getting the error codes listed above. We did not replace the shifter module or any other parts to resolve this issue. After leaving the key in the ignition for several hours, the key synchronized with the car.
If you have Star Diagnostic Scanner with Xentry such as the C3 or the Connect4, there is an option to carry out this procedure and speed up the process. Honestly, we are not sure why it takes so long. Maybe Mercedes-Benz didn’t want someone to generate new keys from dumps and try to steal a Mercedes-Benz in just minutes. What thief would sit on a Mercedes-Benz for 5+ hours until the car recognizes the key?