The official notice
Defect
On certain vehicles, the air conditioning drain hoses may not be installed correctly. This could allow condensation water from the air conditioner to enter the passenger compartment. If this happens, nearby electrical components could corrode and/or short circuit. This could cause some electrical systems not to work properly. This includes: an inability to unlock or start the vehicle, the automatic emergency call (eCall) system may not be available, and the engine "limp home mode" could be activated.
Safety Risk
A short circuit could create the risk of a fire. The failure of other electrical components could increase the risk of injury or a crash.
Remedy
Mercedes-Benz will notify owners by mail and instruct them to take their vehicle to a dealer to inspect the air conditioning drain hoses, and correct their installation if necessary.