
If they conclude that the Ignition Switch (EIS-EZS) is the culprit, you will be told that the switch must be replaced. You may consider taking your car to the dealer or an independent shop and having them troubleshoot the problem. Hopefully, there are fault codes that will point you to the problem.ĭiagnosing Mercedes ignition problems isn’t a simple DIY job. If the ignition turns intermittently, consider yourself lucky and scan for codes.

The only issue here is that if you can’t turn on the ignition, you can’t power on the OBD2 port and the scanner. If you don’t have this scanner or know of a shop that does, a possible alternative would be to use a YOUCANIC scanner. This scanner should still retrieve fault codes when the ignition is off. Try scanning your Mercedes-Benz for fault codes. If the other key works, keep using it for a couple of weeks to verify that the issue is the key and not the EIS. If you have a spare key, try to see if you are experiencing the same symptoms with the other key. How to fix Mercedes Ignition Switch ProblemsĪ defective key can very well cause these symptoms. That’s not necessarily the only solution see alternatives below. They will recommend that the module be replaced. Mercedes dealers don’t repairer a bad EIS-EZS module. While it can be diagnosed with Start Diagnostic Scanner used at dealerships, it can’t be repaired with this scanner.

