Have Mercedes Questions? Ask a Mechanic for Answers ASAP
Hello, my name is***** for the question. The most common cause of this is a bad battery. Even if the battery is low some of the other systems will work but the module will not allow the starter to engage. I would check the battery first. If that is fine then the problem may be the key or he electronic ignition switch. These do fail all of the time on this vehicle. Let me know if you need more help.