Is it the Key, or a Tripped Security Protocol?

With the intricate electronic functions of your Mercedes, a tripped security protocol in the Driver Authorization System (DAS) can present as a key problem. Here is a rundown of the DAS operates to validate you, the driver, before allowing the car to start—and how you can spot something amiss.

Most Mercedes Benz cars produced after the year 2000 use DAS to validate the driver/key fob. The computer chip inside the key must properly communicate with the car’s electronics in order for it to authorize that this is indeed the proper key, thus the proper owner and driver, and allow the car to start.

Each time the key is placed in the ignition switch, the serial number is transmitted to the car to match what it has programmed. If it matches, the key will turn and the car starts. If it doesn’t, the system locks down and won’t start without a visit to a factory-certified mechanic, because the car is essentially programmed to believe that an unauthorized driver is trying to use the car.  

We all know that computers and electronics can fail, even if we’re doing everything right and even if all the modules and components are state of the art. While you can feel assured that your Benz will not easily fall into the wrong hands, you may still have to deal with key fob issues or security protocol errors.

Fortunately, it’s easy and cheap to get your key tested. And that’s a much smaller-scale repair cost compared to working with the electronic modules of your Mercedes’ Driver Authorization System and Electronic Ignition Switch. We recommend ruling that out before towing the car to a trusted mechanic or the dealership.